use actix_web::web::Data;
use actix_web::{HttpRequest, HttpResponse, Responder, get, web};
use chrono::LocalResult::{Ambiguous, Single};
use chrono::{DateTime, Datelike, FixedOffset, Local, LocalResult, NaiveDate, TimeZone, Utc};
use log::{debug, trace, warn};
use opentelemetry::KeyValue;
use opentelemetry::trace::{Span, Status, TraceContextExt, Tracer};
use rayon::prelude::*;
use serde::{Deserialize, Serialize};
use std::collections::HashSet;
use std::path::Path;
use std::path::PathBuf;
use std::sync::Mutex;
use walkdir::WalkDir;

use crate::data::Claims;
use crate::database::ExifDao;
use crate::files::is_image_or_video;
use crate::otel::{extract_context_from_request, global_tracer};
use crate::state::AppState;

// Helper that encapsulates path-exclusion semantics
#[derive(Debug)]
struct PathExcluder {
    excluded_dirs: Vec<PathBuf>,
    excluded_patterns: Vec<String>,
}

impl PathExcluder {
    /// Build from a `base` path and the raw exclusion entries.
    ///
    /// Rules:
    /// - Entries starting with '/' are interpreted as "absolute under base"
    ///   (e.g. "/photos/private" -> base/photos/private).
    /// - Entries without '/' are treated as substring patterns that match
    ///   anywhere in the full path string (still scoped under base).
    fn new(base: &Path, raw_excluded: &[String]) -> Self {
        let mut excluded_dirs = Vec::new();
        let mut excluded_patterns = Vec::new();

        for dir in raw_excluded {
            if let Some(rel) = dir.strip_prefix('/') {
                // Absolute under base
                if !rel.is_empty() {
                    excluded_dirs.push(base.join(rel));
                }
            } else {
                // Pattern anywhere under base
                excluded_patterns.push(dir.clone());
            }
        }

        debug!(
            "PathExcluder created. dirs={:?}, patterns={:?}",
            excluded_dirs, excluded_patterns
        );

        Self {
            excluded_dirs,
            excluded_patterns,
        }
    }

    /// Returns true if `path` should be excluded.
    fn is_excluded(&self, path: &Path) -> bool {
        // Directory-based exclusions
        for excluded in &self.excluded_dirs {
            if path.starts_with(excluded) {
                trace!(
                    "PathExcluder: excluded by dir: {:?} (rule: {:?})",
                    path, excluded
                );
                return true;
            }
        }

        // Pattern-based exclusions: match whole path components (dir or file name),
        // not substrings.
        if !self.excluded_patterns.is_empty() {
            for component in path.components() {
                if let Some(comp_str) = component.as_os_str().to_str()
                    && self.excluded_patterns.iter().any(|pat| pat == comp_str)
                {
                    trace!(
                        "PathExcluder: excluded by component pattern: {:?} (component: {:?}, patterns: {:?})",
                        path, comp_str, self.excluded_patterns
                    );
                    return true;
                }
            }
        }

        false
    }
}

#[derive(Copy, Clone, Deserialize, PartialEq, Debug)]
#[serde(rename_all = "lowercase")]
pub enum MemoriesSpan {
    Day,
    Week,
    Month,
}

#[derive(Deserialize)]
pub struct MemoriesRequest {
    pub span: Option<MemoriesSpan>,
    /// Client timezone offset in minutes from UTC (e.g., -480 for PST, 60 for CET)
    pub timezone_offset_minutes: Option<i32>,
}

#[derive(Debug, Serialize, Clone)]
pub struct MemoryItem {
    pub path: String,
    pub created: Option<i64>,
    pub modified: Option<i64>,
}

#[derive(Debug, Serialize)]
pub struct MemoriesResponse {
    pub items: Vec<MemoryItem>,
}

/// Convert Unix timestamp to NaiveDate in client timezone
fn timestamp_to_naive_date(
    timestamp: i64,
    client_timezone: &Option<FixedOffset>,
) -> Option<NaiveDate> {
    let dt_utc = DateTime::<Utc>::from_timestamp(timestamp, 0)?;

    let date = if let Some(tz) = client_timezone {
        dt_utc.with_timezone(tz).date_naive()
    } else {
        dt_utc.with_timezone(&Local).date_naive()
    };

    Some(date)
}

pub fn extract_date_from_filename(filename: &str) -> Option<DateTime<FixedOffset>> {
    let build_date_from_ymd_capture =
        |captures: &regex::Captures| -> Option<DateTime<FixedOffset>> {
            let year = captures.get(1)?.as_str().parse::<i32>().ok()?;
            let month = captures.get(2)?.as_str().parse::<u32>().ok()?;
            let day = captures.get(3)?.as_str().parse::<u32>().ok()?;
            let hour = captures.get(4)?.as_str().parse::<u32>().ok()?;
            let min = captures.get(5)?.as_str().parse::<u32>().ok()?;
            let sec = captures.get(6)?.as_str().parse::<u32>().ok()?;

            match Local.from_local_datetime(
                &NaiveDate::from_ymd_opt(year, month, day)?.and_hms_opt(hour, min, sec)?,
            ) {
                Single(dt) => Some(dt.fixed_offset()),
                Ambiguous(early_dt, _) => Some(early_dt.fixed_offset()),
                LocalResult::None => {
                    warn!("Weird local date: {:?}", filename);
                    None
                }
            }
        };

    // 1. Screenshot format: Screenshot_2014-06-01-20-44-50.png
    if let Some(captures) = regex::Regex::new(r"(\d{4})-(\d{2})-(\d{2})-(\d{2})-(\d{2})-(\d{2})")
        .ok()?
        .captures(filename)
        .and_then(|c| build_date_from_ymd_capture(&c))
    {
        return Some(captures);
    }

    // Screenshot format: Screenshot_20140601[_-]204450.png
    if let Some(captures) = regex::Regex::new(r"(\d{4})(\d{2})(\d{2})[_-](\d{2})(\d{2})(\d{2})")
        .ok()?
        .captures(filename)
        .and_then(|c| build_date_from_ymd_capture(&c))
    {
        return Some(captures);
    }

    // 2. Dash format: 2015-01-09_02-15-15.jpg
    if let Some(captures) = regex::Regex::new(r"(\d{4})-(\d{2})-(\d{2})_(\d{2})-(\d{2})-(\d{2})")
        .ok()?
        .captures(filename)
        .and_then(|c| build_date_from_ymd_capture(&c))
    {
        return Some(captures);
    }

    // Dash with compact time format: 2015-01-09-021515.jpg
    if let Some(captures) = regex::Regex::new(r"(\d{4})-(\d{2})-(\d{2})-(\d{2})(\d{2})(\d{2})")
        .ok()?
        .captures(filename)
        .and_then(|c| build_date_from_ymd_capture(&c))
    {
        return Some(captures);
    }

    // 3. Compact format: 20140927101712.jpg
    if let Some(captures) = regex::Regex::new(r"(\d{4})(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})")
        .ok()?
        .captures(filename)
        .and_then(|c| build_date_from_ymd_capture(&c))
    {
        return Some(captures);
    }

    // 4. Timestamp format: 1401638400.jpeg, att_1422489664680106.jpeg, att_142248967186928.jpeg
    // Matches timestamps with 10-16 digits (seconds, milliseconds, microseconds)
    if let Some(captures) = regex::Regex::new(r"(\d{10,16})\.").ok()?.captures(filename) {
        let timestamp_str = captures.get(1)?.as_str();
        let len = timestamp_str.len();

        // Skip autogenerated filenames that start with "10000" (e.g., 1000004178.jpg)
        // These are not timestamps but auto-generated file IDs
        if timestamp_str.starts_with("10000") {
            return None;
        }

        // Try milliseconds first (13 digits exactly)
        if len == 13
            && let Some(date_time) = timestamp_str
                .parse::<i64>()
                .ok()
                .and_then(DateTime::from_timestamp_millis)
                .map(|naive_dt| naive_dt.fixed_offset())
        {
            return Some(date_time);
        }

        // For 14-16 digits, treat first 10 digits as seconds to avoid far future dates
        // Examples: att_1422489664680106 (16 digits), att_142248967186928 (15 digits)
        if (14..=16).contains(&len)
            && let Some(date_time) = timestamp_str[0..10]
                .parse::<i64>()
                .ok()
                .and_then(|timestamp_secs| DateTime::from_timestamp(timestamp_secs, 0))
                .map(|naive_dt| naive_dt.fixed_offset())
        {
            return Some(date_time);
        }

        // Exactly 10 digits - seconds since epoch
        if len == 10
            && let Some(date_time) = timestamp_str
                .parse::<i64>()
                .ok()
                .and_then(|timestamp_secs| DateTime::from_timestamp(timestamp_secs, 0))
                .map(|naive_dt| naive_dt.fixed_offset())
        {
            return Some(date_time);
        }

        // 11-12 digits: try as milliseconds (might be partial millisecond timestamp)
        if (len == 11 || len == 12)
            && let Some(date_time) = timestamp_str
                .parse::<i64>()
                .ok()
                .and_then(DateTime::from_timestamp_millis)
                .map(|naive_dt| naive_dt.fixed_offset())
        {
            return Some(date_time);
        }
    }

    None
}

/// Get the canonical date for a memory with priority: filename → EXIF → metadata
/// Returns (NaiveDate for matching, timestamp for display, modified timestamp)
fn get_memory_date_with_priority(
    path: &Path,
    exif_date_taken: Option<i64>,
    client_timezone: &Option<FixedOffset>,
) -> Option<(NaiveDate, Option<i64>, Option<i64>)> {
    // Read file metadata once
    let meta = std::fs::metadata(path).ok()?;

    // Priority 1: Try to extract date from filename
    if let Some(filename_date) = path
        .file_name()
        .and_then(|f| f.to_str())
        .and_then(extract_date_from_filename)
    {
        // Convert to client timezone if specified
        let date_in_timezone = if let Some(tz) = client_timezone {
            filename_date.with_timezone(tz)
        } else {
            filename_date.with_timezone(&Local).fixed_offset()
        };

        let timestamp = if let Some(tz) = client_timezone {
            filename_date.with_timezone(tz).timestamp()
        } else {
            filename_date.timestamp()
        };

        let modified = meta.modified().ok().map(|t| {
            let utc: DateTime<Utc> = t.into();
            if let Some(tz) = client_timezone {
                utc.with_timezone(tz).timestamp()
            } else {
                utc.timestamp()
            }
        });

        debug!(
            "Memory date from filename {:?} > {:?} = {:?}",
            path.file_name(),
            filename_date,
            date_in_timezone
        );
        return Some((date_in_timezone.date_naive(), Some(timestamp), modified));
    }

    // Priority 2: Use EXIF date_taken if available
    if let Some(exif_timestamp) = exif_date_taken {
        let date = timestamp_to_naive_date(exif_timestamp, client_timezone)?;

        let modified = meta.modified().ok().map(|t| {
            let utc: DateTime<Utc> = t.into();
            if let Some(tz) = client_timezone {
                utc.with_timezone(tz).timestamp()
            } else {
                utc.timestamp()
            }
        });

        debug!("Memory date from EXIF {:?} = {:?}", path.file_name(), date);
        return Some((date, Some(exif_timestamp), modified));
    }

    // Priority 3: Fall back to metadata
    let system_time = meta.created().ok().or_else(|| meta.modified().ok())?;
    let dt_utc: DateTime<Utc> = system_time.into();

    let date_in_timezone = if let Some(tz) = client_timezone {
        dt_utc.with_timezone(tz).date_naive()
    } else {
        dt_utc.with_timezone(&Local).date_naive()
    };

    let created_timestamp = if let Some(tz) = client_timezone {
        dt_utc.with_timezone(tz).timestamp()
    } else {
        dt_utc.timestamp()
    };

    let modified = meta.modified().ok().map(|t| {
        let utc: DateTime<Utc> = t.into();
        if let Some(tz) = client_timezone {
            utc.with_timezone(tz).timestamp()
        } else {
            utc.timestamp()
        }
    });

    trace!("Fallback metadata create date = {:?}", date_in_timezone);
    Some((date_in_timezone, Some(created_timestamp), modified))
}

/// Collect memories from EXIF database
fn collect_exif_memories(
    exif_dao: &Data<Mutex<Box<dyn ExifDao>>>,
    context: &opentelemetry::Context,
    base_path: &str,
    now: NaiveDate,
    span_mode: MemoriesSpan,
    years_back: u32,
    client_timezone: &Option<FixedOffset>,
    path_excluder: &PathExcluder,
) -> Vec<(MemoryItem, NaiveDate)> {
    // Query database for all files with date_taken
    let exif_records = match exif_dao.lock() {
        Ok(mut dao) => match dao.get_all_with_date_taken(context) {
            Ok(records) => records,
            Err(e) => {
                warn!("Failed to query EXIF database: {:?}", e);
                return Vec::new(); // Graceful fallback
            }
        },
        Err(e) => {
            warn!("Failed to lock EXIF DAO: {:?}", e);
            return Vec::new();
        }
    };

    // Parallel processing with Rayon
    exif_records
        .par_iter()
        .filter_map(|(file_path, date_taken_ts)| {
            // Build full path
            let full_path = Path::new(base_path).join(file_path);

            // Check exclusions
            if path_excluder.is_excluded(&full_path) {
                return None;
            }

            // Verify file exists
            if !full_path.exists() || !full_path.is_file() {
                warn!("EXIF record exists but file not found: {:?}", full_path);
                return None;
            }

            // Get date with priority: filename → EXIF → metadata
            // This ensures sorting and display use the same date source
            let (file_date, created, modified) =
                get_memory_date_with_priority(&full_path, Some(*date_taken_ts), client_timezone)?;

            // Check if matches memory criteria
            if !is_memories_match(file_path, file_date, now, span_mode, years_back) {
                return None;
            }

            Some((
                MemoryItem {
                    path: file_path.clone(),
                    created,
                    modified,
                },
                file_date,
            ))
        })
        .collect()
}

/// Collect memories from file system scan (for files not in EXIF DB)
fn collect_filesystem_memories(
    base_path: &str,
    path_excluder: &PathExcluder,
    skip_paths: &HashSet<PathBuf>,
    now: NaiveDate,
    span_mode: MemoriesSpan,
    years_back: u32,
    client_timezone: &Option<FixedOffset>,
) -> Vec<(MemoryItem, NaiveDate)> {
    let base = Path::new(base_path);

    let entries: Vec<_> = WalkDir::new(base)
        .into_iter()
        .filter_map(|e| e.ok())
        .filter(|e| {
            let path = e.path();

            // Skip if already processed by EXIF query
            if skip_paths.contains(path) {
                return false;
            }

            // Check exclusions
            if path_excluder.is_excluded(path) {
                return false;
            }

            // Only process image/video files
            e.file_type().is_file() && is_image_or_video(path)
        })
        .collect();

    entries
        .par_iter()
        .filter_map(|entry| {
            // Use unified date priority function (no EXIF for filesystem scan)
            let (file_date, created, modified) =
                get_memory_date_with_priority(entry.path(), None, client_timezone)?;

            if is_memories_match(
                entry.path().to_str().unwrap_or("Unknown"),
                file_date,
                now,
                span_mode,
                years_back,
            ) {
                let path_relative = entry.path().strip_prefix(base).ok()?.to_str()?.to_string();

                Some((
                    MemoryItem {
                        path: path_relative,
                        created,
                        modified,
                    },
                    file_date,
                ))
            } else {
                None
            }
        })
        .collect()
}

#[get("/memories")]
pub async fn list_memories(
    _claims: Claims,
    request: HttpRequest,
    q: web::Query<MemoriesRequest>,
    app_state: Data<AppState>,
    exif_dao: Data<Mutex<Box<dyn ExifDao>>>,
) -> impl Responder {
    let tracer = global_tracer();
    let parent_context = extract_context_from_request(&request);
    let mut span = tracer.start_with_context("list_memories", &parent_context);
    let span_context =
        opentelemetry::Context::new().with_remote_span_context(span.span_context().clone());

    let span_mode = q.span.unwrap_or(MemoriesSpan::Day);
    let years_back: u32 = 15;

    // Create timezone from client offset, default to local timezone if not provided
    let client_timezone = match q.timezone_offset_minutes {
        Some(offset_mins) => {
            let offset_secs = offset_mins * 60;
            Some(
                FixedOffset::east_opt(offset_secs)
                    .unwrap_or_else(|| FixedOffset::east_opt(0).unwrap()),
            )
        }
        None => None,
    };

    let now = if let Some(tz) = client_timezone {
        debug!("Client timezone: {:?}", tz);
        Utc::now().with_timezone(&tz).date_naive()
    } else {
        Local::now().date_naive()
    };

    debug!("Now: {:?}", now);

    let base = Path::new(&app_state.base_path);

    // Build the path excluder from base and env-configured exclusions
    let path_excluder = PathExcluder::new(base, &app_state.excluded_dirs);

    // Phase 1: Query EXIF database
    let exif_memories = collect_exif_memories(
        &exif_dao,
        &span_context,
        &app_state.base_path,
        now,
        span_mode,
        years_back,
        &client_timezone,
        &path_excluder,
    );

    // Build HashSet for deduplication
    let exif_paths: HashSet<PathBuf> = exif_memories
        .iter()
        .map(|(item, _)| PathBuf::from(&app_state.base_path).join(&item.path))
        .collect();

    // Phase 2: File system scan (skip EXIF files)
    let fs_memories = collect_filesystem_memories(
        &app_state.base_path,
        &path_excluder,
        &exif_paths,
        now,
        span_mode,
        years_back,
        &client_timezone,
    );

    // Phase 3: Merge and sort
    let mut memories_with_dates = exif_memories;
    memories_with_dates.extend(fs_memories);

    match span_mode {
        // Sort by absolute time for a more 'overview'
        MemoriesSpan::Month => memories_with_dates.sort_by(|a, b| a.1.cmp(&b.1)),
        // For week span, sort by day of month, then by full timestamp (oldest first)
        MemoriesSpan::Week => {
            memories_with_dates.sort_by(|a, b| {
                // First, sort by day of month
                let day_cmp = a.1.day().cmp(&b.1.day());
                if day_cmp != std::cmp::Ordering::Equal {
                    return day_cmp;
                }

                // Then sort by full created timestamp (oldest to newest)
                match (a.0.created, b.0.created) {
                    (Some(a_time), Some(b_time)) => a_time.cmp(&b_time),
                    (Some(_), None) => std::cmp::Ordering::Less,
                    (None, Some(_)) => std::cmp::Ordering::Greater,
                    (None, None) => std::cmp::Ordering::Equal,
                }
            });
        }
        // For day span, sort by day of month then by time
        MemoriesSpan::Day => {
            memories_with_dates.sort_by(|a, b| {
                let day_comparison = a.1.day().cmp(&b.1.day());

                if day_comparison == std::cmp::Ordering::Equal {
                    match (a.0.created, b.0.created) {
                        (Some(a_time), Some(b_time)) => a_time.cmp(&b_time),
                        (Some(_), None) => std::cmp::Ordering::Less,
                        (None, Some(_)) => std::cmp::Ordering::Greater,
                        (None, None) => std::cmp::Ordering::Equal,
                    }
                } else {
                    day_comparison
                }
            });
        }
    }
    // Sort by day of the month and time (using the created timestamp)

    let items: Vec<MemoryItem> = memories_with_dates.into_iter().map(|(m, _)| m).collect();

    span.add_event(
        "memories_scanned",
        vec![
            KeyValue::new("span", format!("{:?}", span_mode)),
            KeyValue::new("years_back", years_back.to_string()),
            KeyValue::new("result_count", items.len().to_string()),
            KeyValue::new(
                "client_timezone",
                format!(
                    "{:?}",
                    client_timezone.unwrap_or_else(|| FixedOffset::east_opt(0).unwrap())
                ),
            ),
            KeyValue::new("excluded_dirs", format!("{:?}", app_state.excluded_dirs)),
        ],
    );
    span.set_status(Status::Ok);

    HttpResponse::Ok().json(MemoriesResponse { items })
}

fn is_memories_match(
    file_path: &str,
    file_date: NaiveDate,
    today: NaiveDate,
    span: MemoriesSpan,
    years_back: u32,
) -> bool {
    if file_date > today {
        return false;
    }
    let years_diff = (today.year() - file_date.year()).unsigned_abs();
    if years_diff > years_back {
        warn!(
            "File ({}) date is too far in the past: {:?} vs {:?}",
            file_path, file_date, today
        );
        return false;
    }

    match span {
        MemoriesSpan::Day => same_month_day_any_year(file_date, today),
        MemoriesSpan::Week => same_week_any_year(file_date, today),
        MemoriesSpan::Month => same_month_any_year(file_date, today),
    }
}

fn same_month_day_any_year(a: NaiveDate, b: NaiveDate) -> bool {
    a.month() == b.month() && a.day() == b.day()
}

// Match same ISO week number and same weekday (ignoring year)
fn same_week_any_year(a: NaiveDate, b: NaiveDate) -> bool {
    a.iso_week().week().eq(&b.iso_week().week())
}

// Match same month (ignoring day and year)
fn same_month_any_year(a: NaiveDate, b: NaiveDate) -> bool {
    a.month() == b.month()
}

#[cfg(test)]
mod tests {
    use super::*;
    use chrono::Timelike;
    use std::fs::{self, File};
    use tempfile::tempdir;

    #[test]
    fn test_extract_date_from_filename_screenshot_format() {
        let filename = "Screenshot_2014-06-01-20-44-50.png";
        let date_time = extract_date_from_filename(filename).unwrap();

        assert_eq!(date_time.year(), 2014);
        assert_eq!(date_time.month(), 6);
        assert_eq!(date_time.day(), 1);
        assert_eq!(date_time.hour(), 20);
        assert_eq!(date_time.minute(), 44);
        assert_eq!(date_time.second(), 50);
    }

    #[test]
    fn test_extract_date_from_filename_screenshot_less_dashes_format() {
        let filename = "Screenshot_20140601-204450.png";
        let date_time = extract_date_from_filename(filename).unwrap();

        assert_eq!(date_time.year(), 2014);
        assert_eq!(date_time.month(), 6);
        assert_eq!(date_time.day(), 1);
        assert_eq!(date_time.hour(), 20);
        assert_eq!(date_time.minute(), 44);
        assert_eq!(date_time.second(), 50);
    }

    #[test]
    fn test_extract_date_from_filename_screenshot_underscores_format() {
        let filename = "20140601_204450.png";
        let date_time = extract_date_from_filename(filename).unwrap();

        assert_eq!(date_time.year(), 2014);
        assert_eq!(date_time.month(), 6);
        assert_eq!(date_time.day(), 1);
        assert_eq!(date_time.hour(), 20);
        assert_eq!(date_time.minute(), 44);
        assert_eq!(date_time.second(), 50);
    }

    #[test]
    fn test_extract_date_from_filename_dash_format() {
        let filename = "2015-01-09_02-15-15.jpg";
        let date_time = extract_date_from_filename(filename).unwrap();

        assert_eq!(date_time.year(), 2015);
        assert_eq!(date_time.month(), 1);
        assert_eq!(date_time.day(), 9);
        assert_eq!(date_time.hour(), 2);
        assert_eq!(date_time.minute(), 15);
        assert_eq!(date_time.second(), 15);
    }

    #[test]
    fn test_extract_date_from_filename_dash_compact_time_format() {
        let filename = "2015-01-09-021515.jpg";
        let date_time = extract_date_from_filename(filename).unwrap();

        assert_eq!(date_time.year(), 2015);
        assert_eq!(date_time.month(), 1);
        assert_eq!(date_time.day(), 9);
        assert_eq!(date_time.hour(), 2);
        assert_eq!(date_time.minute(), 15);
        assert_eq!(date_time.second(), 15);
    }

    #[test]
    fn test_extract_date_from_filename_compact_format() {
        let filename = "20140927101712.jpg";
        let date_time = extract_date_from_filename(filename).unwrap();

        assert_eq!(date_time.year(), 2014);
        assert_eq!(date_time.month(), 9);
        assert_eq!(date_time.day(), 27);
        assert_eq!(date_time.hour(), 10);
        assert_eq!(date_time.minute(), 17);
        assert_eq!(date_time.second(), 12);
    }

    #[test]
    fn test_extract_date_from_filename_timestamp_format() {
        let filename = "xyz_1401638400.jpeg"; // Unix timestamp for 2014-06-01 16:00:00 UTC
        // Timestamps are already in UTC, so timezone doesn't matter for this test
        let date_time = extract_date_from_filename(filename).unwrap();

        assert_eq!(date_time.year(), 2014);
        assert_eq!(date_time.month(), 6);
        assert_eq!(date_time.day(), 1);
        assert_eq!(date_time.hour(), 16);
        assert_eq!(date_time.minute(), 0);
        assert_eq!(date_time.second(), 0);
    }

    #[test]
    fn test_extract_date_from_filename_timestamp_millis_format() {
        let filename = "xyz_1401638400000.jpeg"; // Unix timestamp in milliseconds
        let date_time = extract_date_from_filename(filename).unwrap();

        assert_eq!(date_time.year(), 2014);
        assert_eq!(date_time.month(), 6);
        assert_eq!(date_time.day(), 1);
        assert_eq!(date_time.hour(), 16);
        assert_eq!(date_time.minute(), 0);
        assert_eq!(date_time.second(), 0);
    }

    #[test]
    fn test_extract_date_from_filename_attachment_15_digits() {
        // att_142248967186928.jpeg - 15 digits, should parse first 10 as seconds
        // 1422489671 = 2015-01-28 23:07:51 UTC (converts to local timezone)
        let filename = "att_142248967186928.jpeg";
        let date_time = extract_date_from_filename(filename).unwrap();

        // Verify year and month are correct (2015-01)
        assert_eq!(date_time.year(), 2015);
        assert_eq!(date_time.month(), 1);
        // Day may be 28 or 29 depending on timezone
        assert!(date_time.day() >= 28 && date_time.day() <= 29);

        // Verify timestamp is within expected range (should be around 1422489671)
        let timestamp = date_time.timestamp();
        assert!(timestamp >= 1422480000 && timestamp <= 1422576000); // Jan 28-29, 2015
    }

    #[test]
    fn test_extract_date_from_filename_attachment_16_digits() {
        // att_1422489664680106.jpeg - 16 digits, should parse first 10 as seconds
        // 1422489664 = 2015-01-28 23:07:44 UTC (converts to local timezone)
        let filename = "att_1422489664680106.jpeg";
        let date_time = extract_date_from_filename(filename).unwrap();

        // Verify year and month are correct (2015-01)
        assert_eq!(date_time.year(), 2015);
        assert_eq!(date_time.month(), 1);
        // Day may be 28 or 29 depending on timezone
        assert!(date_time.day() >= 28 && date_time.day() <= 29);

        // Verify timestamp is within expected range (should be around 1422489664)
        let timestamp = date_time.timestamp();
        assert!(timestamp >= 1422480000 && timestamp <= 1422576000); // Jan 28-29, 2015
    }

    #[test]
    fn test_extract_date_from_filename_autogenerated_should_not_match() {
        // Autogenerated filenames like 1000004178.jpg should NOT be parsed as timestamps
        // These start with "10000" which would be Sept 2001 if parsed literally
        let filename = "1000004178.jpg";
        let date_time = extract_date_from_filename(filename);

        assert!(
            date_time.is_none(),
            "Autogenerated filenames starting with 10000 should not be parsed as dates"
        );
    }

    #[test]
    fn test_memory_date_priority_filename() {
        let temp_dir = tempdir().unwrap();
        let temp_file = temp_dir.path().join("Screenshot_2014-06-01-20-44-50.png");
        File::create(&temp_file).unwrap();

        // Test that filename takes priority (even with EXIF data available)
        let exif_date = DateTime::<Utc>::from_timestamp(1609459200, 0) // 2021-01-01
            .unwrap()
            .timestamp();

        let (date, created, _) = get_memory_date_with_priority(
            &temp_file,
            Some(exif_date),
            &Some(*Local::now().fixed_offset().offset()),
        )
        .unwrap();

        // Check that date is from filename (2014), NOT EXIF (2021)
        assert_eq!(date.year(), 2014);
        assert_eq!(date.month(), 6);
        assert_eq!(date.day(), 1);

        // Check that created timestamp matches the date from filename
        assert!(created.is_some());
        let ts = created.unwrap();
        // The timestamp should be for 2014-06-01 20:44:50 in the LOCAL timezone
        let dt_from_ts = Local.timestamp_opt(ts, 0).unwrap();
        assert_eq!(dt_from_ts.year(), 2014);
        assert_eq!(dt_from_ts.month(), 6);
        assert_eq!(dt_from_ts.day(), 1);
        assert_eq!(dt_from_ts.hour(), 20);
        assert_eq!(dt_from_ts.minute(), 44);
        assert_eq!(dt_from_ts.second(), 50);
    }

    #[test]
    fn test_memory_date_priority_metadata_fallback() {
        let temp_dir = tempdir().unwrap();
        let temp_file = temp_dir.path().join("regular_image.jpg");
        File::create(&temp_file).unwrap();

        // Test metadata fallback when no filename date or EXIF
        let (date, created, modified) =
            get_memory_date_with_priority(&temp_file, None, &None).unwrap();

        // Both date and timestamps should be from metadata (recent)
        let today = Local::now().date_naive();
        assert_eq!(date.year(), today.year());
        assert_eq!(date.month(), today.month());

        // Both timestamps should be valid
        assert!(created.is_some());
        assert!(modified.is_some());

        // Check that timestamps are recent
        let dt_created = DateTime::<Utc>::from_timestamp(created.unwrap(), 0).unwrap();
        assert_eq!(dt_created.year(), today.year());

        let dt_modified = DateTime::<Utc>::from_timestamp(modified.unwrap(), 0).unwrap();
        assert_eq!(dt_modified.year(), today.year());
    }

    #[test]
    fn test_memory_date_priority_exif_over_metadata() {
        let temp_dir = tempdir().unwrap();
        let temp_file = temp_dir.path().join("regular_image.jpg");
        File::create(&temp_file).unwrap();

        // Test that EXIF takes priority over metadata (but not filename)
        // EXIF date: June 15, 2020 12:00:00 UTC (safe from timezone edge cases)
        let exif_date = DateTime::<Utc>::from_timestamp(1592222400, 0) // 2020-06-15 12:00:00 UTC
            .unwrap()
            .timestamp();

        let (date, created, modified) =
            get_memory_date_with_priority(&temp_file, Some(exif_date), &None).unwrap();

        // Date should be from EXIF (2020), not metadata (today)
        assert_eq!(date.year(), 2020);
        assert_eq!(date.month(), 6);
        assert_eq!(date.day(), 15);

        // Created timestamp should also be from EXIF
        assert!(created.is_some());
        assert_eq!(created.unwrap(), exif_date);

        // Modified should still be from metadata
        assert!(modified.is_some());
        let today = Local::now().date_naive();
        let dt_modified = DateTime::<Utc>::from_timestamp(modified.unwrap(), 0).unwrap();
        assert_eq!(dt_modified.year(), today.year());
    }

    #[test]
    fn test_path_excluder_absolute_under_base() {
        let tmp = tempdir().unwrap();
        let base = tmp.path();

        // Simulate structure:
        // base/photos/private/secret.jpg
        // base/photos/public/ok.jpg
        // base/screenshots/img.png
        let photos_private = base.join("photos/private");
        let photos_public = base.join("photos/public");
        let screenshots = base.join("screenshots");

        fs::create_dir_all(&photos_private).unwrap();
        fs::create_dir_all(&photos_public).unwrap();
        fs::create_dir_all(&screenshots).unwrap();

        let secret = photos_private.join("secret.jpg");
        let ok = photos_public.join("ok.jpg");
        let shot = screenshots.join("img.png");

        File::create(&secret).unwrap();
        File::create(&ok).unwrap();
        File::create(&shot).unwrap();

        // Exclude "/photos/private" and "/screenshots" under base
        let excluded = vec![
            String::from("/photos/private"),
            String::from("/screenshots"),
        ];
        let excluder = PathExcluder::new(base, &excluded);

        assert!(excluder.is_excluded(&secret), "secret should be excluded");
        assert!(
            excluder.is_excluded(&shot),
            "screenshots should be excluded"
        );
        assert!(
            !excluder.is_excluded(&ok),
            "public photo should NOT be excluded"
        );
    }

    #[test]
    fn test_path_excluder_pattern_anywhere_under_base() {
        let tmp = tempdir().unwrap();
        let base = tmp.path();

        // Simulate:
        // base/a/tmp_file.jpg
        // base/b/normal.jpg
        // base/c/sometmpdir/file.jpg
        let a = base.join("a");
        let b = base.join("b");
        let c = base.join("c/tmp");

        fs::create_dir_all(&a).unwrap();
        fs::create_dir_all(&b).unwrap();
        fs::create_dir_all(&c).unwrap();

        let tmp_file = a.join("tmp_file.jpg");
        let normal = b.join("normal.jpg");
        let tmp_dir_file = c.join("file.jpg");

        File::create(&tmp_file).unwrap();
        File::create(&normal).unwrap();
        File::create(&tmp_dir_file).unwrap();

        // Exclude any path containing "tmp"
        let excluded = vec![String::from("tmp")];
        let excluder = PathExcluder::new(base, &excluded);

        assert!(
            !excluder.is_excluded(&tmp_file),
            "file with 'tmp' in name should NOT be excluded"
        );
        assert!(
            excluder.is_excluded(&tmp_dir_file),
            "file in directory with 'tmp' in path should be excluded"
        );
        assert!(
            !excluder.is_excluded(&normal),
            "file without 'tmp' in its path should NOT be excluded"
        );
    }

    #[test]
    fn test_path_excluder_mixed_absolute_and_pattern() {
        let tmp = tempdir().unwrap();
        let base = tmp.path();

        // Simulate:
        // base/photos/private/secret_tmp.jpg  -> excluded by absolute dir rule
        // base/photos/private/secret.jpg      -> excluded by absolute dir rule
        // base/photos/tmp/public.jpg          -> excluded by pattern "tmp" (dir name)
        // base/photos/public/tmp_public.jpg   -> NOT excluded (file name contains "tmp" but not equal)
        // base/other/keep.jpg                 -> NOT excluded
        let photos_private = base.join("photos/private");
        let photos_tmp = base.join("photos/tmp");
        let photos_public = base.join("photos/public");
        let other = base.join("other");

        fs::create_dir_all(&photos_private).unwrap();
        fs::create_dir_all(&photos_tmp).unwrap();
        fs::create_dir_all(&photos_public).unwrap();
        fs::create_dir_all(&other).unwrap();

        let secret_tmp = photos_private.join("secret_tmp.jpg");
        let secret = photos_private.join("secret.jpg");
        let tmp_dir_file = photos_tmp.join("public.jpg");
        let tmp_in_name = photos_public.join("tmp_public.jpg");
        let keep = other.join("keep.jpg");

        File::create(&secret_tmp).unwrap();
        File::create(&secret).unwrap();
        File::create(&tmp_dir_file).unwrap();
        File::create(&tmp_in_name).unwrap();
        File::create(&keep).unwrap();

        // Mixed: exclude "/photos/private" (dir) and any component equal to "tmp"
        let excluded = vec![String::from("/photos/private"), String::from("tmp")];
        let excluder = PathExcluder::new(base, &excluded);

        // Entire private tree is excluded by dir rule
        assert!(excluder.is_excluded(&secret_tmp));
        assert!(excluder.is_excluded(&secret));

        // Dir 'tmp' under photos excluded by pattern
        assert!(excluder.is_excluded(&tmp_dir_file));

        // File name containing 'tmp' but not equal should NOT be excluded
        assert!(!excluder.is_excluded(&tmp_in_name));

        // keep.jpg doesn't match any rule
        assert!(!excluder.is_excluded(&keep));
    }

    #[test]
    fn test_week_span_sorting_chronological_by_day() {
        // Test that Week span sorts by:
        // 1. Day of month (ascending)
        // 2. Full timestamp oldest to newest (year + time combined)

        // Create test data:
        // - Jan 15, 2024 at 9:00 AM
        // - Jan 15, 2020 at 10:00 AM
        // - Jan 16, 2021 at 8:00 AM

        let jan_15_2024_9am = NaiveDate::from_ymd_opt(2024, 1, 15)
            .unwrap()
            .and_hms_opt(9, 0, 0)
            .unwrap()
            .and_utc()
            .timestamp();

        let jan_15_2020_10am = NaiveDate::from_ymd_opt(2020, 1, 15)
            .unwrap()
            .and_hms_opt(10, 0, 0)
            .unwrap()
            .and_utc()
            .timestamp();

        let jan_16_2021_8am = NaiveDate::from_ymd_opt(2021, 1, 16)
            .unwrap()
            .and_hms_opt(8, 0, 0)
            .unwrap()
            .and_utc()
            .timestamp();

        let mut memories_with_dates = vec![
            (
                MemoryItem {
                    path: "photo1.jpg".to_string(),
                    created: Some(jan_15_2024_9am),
                    modified: Some(jan_15_2024_9am),
                },
                NaiveDate::from_ymd_opt(2024, 1, 15).unwrap(),
            ),
            (
                MemoryItem {
                    path: "photo2.jpg".to_string(),
                    created: Some(jan_15_2020_10am),
                    modified: Some(jan_15_2020_10am),
                },
                NaiveDate::from_ymd_opt(2020, 1, 15).unwrap(),
            ),
            (
                MemoryItem {
                    path: "photo3.jpg".to_string(),
                    created: Some(jan_16_2021_8am),
                    modified: Some(jan_16_2021_8am),
                },
                NaiveDate::from_ymd_opt(2021, 1, 16).unwrap(),
            ),
        ];

        // Sort using Week span logic
        memories_with_dates.sort_by(|a, b| {
            // First, sort by day of month
            let day_cmp = a.1.day().cmp(&b.1.day());
            if day_cmp != std::cmp::Ordering::Equal {
                return day_cmp;
            }

            // Then sort by full created timestamp (oldest to newest)
            match (a.0.created, b.0.created) {
                (Some(a_time), Some(b_time)) => a_time.cmp(&b_time),
                (Some(_), None) => std::cmp::Ordering::Less,
                (None, Some(_)) => std::cmp::Ordering::Greater,
                (None, None) => std::cmp::Ordering::Equal,
            }
        });

        // Expected order:
        // 1. Jan 15, 2020 at 10:00 AM (oldest Jan 15 photo)
        // 2. Jan 15, 2024 at 9:00 AM (newer Jan 15 photo)
        // 3. Jan 16, 2021 at 8:00 AM (all Jan 16 photos after Jan 15)

        assert_eq!(memories_with_dates[0].0.created.unwrap(), jan_15_2020_10am);
        assert_eq!(memories_with_dates[1].0.created.unwrap(), jan_15_2024_9am);
        assert_eq!(memories_with_dates[2].0.created.unwrap(), jan_16_2021_8am);
    }
}