//! Pipeline-progress reporting for the rip pipeline.
//!
//! v0.13.16 architecture rule: ONE progress signal type. Every long-running
//! pipeline operation (`Disc::copy`, `Disc::patch`, `verify_title`) emits the same
//! `PassProgress` shape via the `Progress` trait. Consumers (autorip) compute
//! a single `PipelineStats` derived view and never reach into per-pass
//! internals.
//!
//! Why this matters: pre-0.13.16 the API leaked `pos`, `bytes_good`,
//! `work_done`, `bytes_pending`, `Finished/NonTrimmed` mapfile semantics —
//! and consumers reinvented the math each time they wanted a percentage.
//! UIs ended up reading one source while server-side computed from another,
//! producing wrong percentages without anyone noticing.

/// Identifies which pipeline phase the progress event belongs to.
///
/// Consumers can render a phase-specific label (e.g. "Sweep", "Trim
/// (reverse)", "Scrape", "Mux") or just use a generic "Pass N" label.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum PassKind {
    /// `Disc::copy` — initial sweep across the entire disc.
    Sweep,
    /// `Disc::patch` retry pass with `block_sectors >= 2`. `reverse=true`
    /// means walking bad ranges from highest to lowest LBA.
    Trim { reverse: bool },
    /// `Disc::patch` final pass at 1 sector per block.
    Scrape { reverse: bool },
    /// Demux ISO → output (MKV / M2TS / network). Single phase that runs
    /// after all rip passes complete.
    Mux,
    /// Sector verification — reads every sector and classifies health.
    Verify,
}

/// One progress sample from a pipeline phase.
///
/// `work_done / work_total` is the per-pass percentage — always 0..=100%
/// regardless of which kind of pass is running. `bytes_good_total` is the
/// cumulative count of confirmed-clean bytes across the whole rip; useful
/// for the "data recovered" stat the user sees.
///
/// For `PassKind::Verify`, the fields map as follows:
/// - `work_done` = sectors read so far
/// - `work_total` = total sectors in title
/// - `bytes_good_total` = good + slow + recovered sectors × 2048
/// - `bytes_unreadable_total` = bad sectors × 2048
/// - `bytes_pending_total` = 0 (verify processes sequentially, nothing pending)
#[derive(Debug, Clone, Copy)]
pub struct PassProgress {
    pub kind: PassKind,
    pub work_done: u64,
    pub work_total: u64,
    pub bytes_good_total: u64,
    pub bytes_unreadable_total: u64,
    pub bytes_pending_total: u64,
    pub bytes_total_disc: u64,
    pub disc_duration_secs: Option<f64>,
    /// How many bytes of the worst-case damage (unreadable + pending) fall
    /// within the main title's extents. Zero means none of the damage
    /// affects the main movie — it's all in extras/menus.
    pub bytes_bad_in_main_title: u64,
    /// Main title duration in seconds. Same as disc_duration_secs when the
    /// disc has one dominant title, but separate so consumers can show both.
    pub main_title_duration_secs: Option<f64>,
    /// Main title size in bytes (sum of extent sizes).
    pub main_title_size_bytes: Option<u64>,
}

impl PassProgress {
    /// Percentage of work completed for this pass (0..=100).
    ///
    /// Returns `100.0` if `work_total` is zero to avoid division by zero.
    pub fn work_pct(&self) -> f64 {
        if self.work_total == 0 {
            return 100.0;
        }
        self.work_done as f64 / self.work_total as f64 * 100.0
    }

    /// Percentage of the disc that is confirmed clean (0..=100).
    ///
    /// Computed from `bytes_good_total / bytes_total_disc`.
    pub fn good_pct(&self) -> f64 {
        if self.bytes_total_disc == 0 {
            return 100.0;
        }
        self.bytes_good_total as f64 / self.bytes_total_disc as f64 * 100.0
    }

    /// Percentage of the disc that is unreadable (0..=100).
    pub fn bad_pct(&self) -> f64 {
        if self.bytes_total_disc == 0 {
            return 0.0;
        }
        self.bytes_unreadable_total as f64 / self.bytes_total_disc as f64 * 100.0
    }

    /// Percentage of the disc that is still pending (not yet attempted or needs retry).
    pub fn pending_pct(&self) -> f64 {
        if self.bytes_total_disc == 0 {
            return 0.0;
        }
        self.bytes_pending_total as f64 / self.bytes_total_disc as f64 * 100.0
    }
}

/// A consumer of pipeline progress events. Library code calls
/// `Progress::report` once per inner-loop iteration (throttling is the
/// consumer's job — `report` is cheap; the library doesn't gate it).
///
/// Returns `true` to continue, `false` to request early stop.
///
/// No `Send`/`Sync` bound — `report` is always called from the same thread
/// running the pipeline, so closures with non-`Sync` captures (e.g.
/// `RefCell<PassProgressState>`) work directly. Blanket impl below lets
/// callers pass closures without explicit struct types.
pub trait Progress {
    fn report(&self, p: &PassProgress) -> bool;
}

impl<F: Fn(&PassProgress) -> bool> Progress for F {
    fn report(&self, p: &PassProgress) -> bool {
        (self)(p)
    }
}