pistonite-cu 0.8.2

use std::sync::{Arc, Mutex};
use std::time::Instant;

use crate::cli::Tick;
use crate::cli::fmt::ansi;
use crate::cli::printer::PRINTER;
use crate::cli::progress::{
    BarFormatter, BarResult, ChildState, ChildStateStrong, Estimater, ProgressBarBuilder,
};

const CHAR_BAR_TICK: char = '\u{251C}'; // |>
const CHAR_BAR: char = '\u{2502}'; // |
const CHAR_TICK: char = '\u{2514}'; // >

/// Handle for a progress bar (This is the internal state, the handle is `Arc<ProgressBar>`)
///
/// See [Progress Bars](fn@crate::progress)
#[derive(Debug)]
pub struct ProgressBar {
    pub(crate) state: StateImmut,
    state_mut: Mutex<State>,
}
impl ProgressBar {
    pub(crate) fn spawn(
        state: StateImmut,
        state_mut: State,
        parent: Option<Arc<Self>>,
    ) -> Arc<Self> {
        let bar = Arc::new(Self {
            state,
            state_mut: Mutex::new(state_mut),
        });
        match parent {
            Some(p) => {
                if let Ok(mut p) = p.state_mut.lock() {
                    p.add_child(&bar);
                }
            }
            None => {
                if let Ok(mut printer) = PRINTER.lock() {
                    if let Some(printer) = printer.as_mut() {
                        printer.add_progress_bar(&bar);
                    }
                }
            }
        }
        bar
    }
    #[doc(hidden)]
    #[inline(always)]
    pub fn __set(self: &Arc<Self>, current: u64, message: Option<String>) {
        if let Ok(mut bar) = self.state_mut.lock() {
            bar.unreal_current = current;
            if let Some(x) = message {
                bar.set_message(&x);
            }
        }
    }

    #[doc(hidden)]
    #[inline(always)]
    pub fn __inc(self: &Arc<Self>, amount: u64, message: Option<String>) {
        if let Ok(mut bar) = self.state_mut.lock() {
            bar.unreal_current = bar.unreal_current.saturating_add(amount);
            if let Some(x) = message {
                bar.set_message(&x);
            }
        }
    }

    /// Set the total steps (if the progress is finite)
    pub fn set_total(&self, total: u64) {
        if total == 0 {
            // 0 is a special value, so we do not allow setting it
            return;
        }
        if let Ok(mut bar) = self.state_mut.lock() {
            bar.unreal_total = total;
        }
    }

    /// Start building a child progress bar
    ///
    /// Note that the child builder will keep this bar alive (displayed), even
    /// if the child is not spawned
    #[inline(always)]
    pub fn child(self: &Arc<Self>, message: impl Into<String>) -> ProgressBarBuilder {
        ProgressBarBuilder::new(message.into()).parent(Some(Arc::clone(self)))
    }

    /// Set the message to be printed and mark the bar as done
    pub fn done_with_message(self: Arc<Self>, message: &str) {
        self.set_done_message(message);
        self.done();
    }

    /// Set the message to be printed and mark the bar as done
    pub fn done_by_ref_with_message(&self, message: &str) {
        self.set_done_message(message);
        self.done_by_ref();
    }

    /// Change the message to be printed when the bar is done.
    /// Useful if information is not available yet when the bar is spawned.
    ///
    /// This does NOT mark the bar as done, use [`done_with_message`](Self::done_with_message)
    /// for that.
    pub fn set_done_message(&self, message: &str) {
        if let Ok(mut bar) = self.state_mut.lock() {
            bar.set_done_message(message);
        }
    }

    /// Change the message to be printed when the bar is interrupted.
    /// Useful if information is not available yet when the bar is spawned.
    pub fn set_interrupted_message(&self, message: &str) {
        if let Ok(mut bar) = self.state_mut.lock() {
            bar.set_interrupted_message(message);
        }
    }

    /// Mark the progress bar as done and drop the handle.
    ///
    /// This needs to be called if the bar is unbounded. Otherwise,
    /// the bar will display in the interrupted state when dropped.
    ///
    /// If the progress is finite, then interrupted state is automatically
    /// determined (`current != total`)
    pub fn done(self: Arc<Self>) {
        if self.state.unbounded {
            if let Ok(mut bar) = self.state_mut.lock() {
                bar.unreal_current = 1;
                bar.unreal_total = 1;
            }
        }
    }

    /// Same as [`done`](Self::done), but does not drop the bar.
    pub fn done_by_ref(&self) {
        if self.state.unbounded {
            if let Ok(mut bar) = self.state_mut.lock() {
                bar.unreal_current = 1;
                bar.unreal_total = 1;
            }
        }
    }

    /// Format the bar
    #[inline(always)]
    pub(crate) fn format(&self, fmt: &mut BarFormatter<'_, '_, '_>) -> i32 {
        self.format_at_depth(0, &mut String::new(), fmt)
    }

    /// Format the bar at depth
    fn format_at_depth(
        &self,
        depth: usize,
        hierarchy: &mut String,
        fmt: &mut BarFormatter<'_, '_, '_>,
    ) -> i32 {
        let Ok(mut bar) = self.state_mut.lock() else {
            return 0;
        };
        bar.format_at_depth(depth, hierarchy, fmt, &self.state)
    }
}

impl Drop for ProgressBar {
    fn drop(&mut self) {
        let result = match self.state_mut.lock() {
            Err(_) => BarResult::DontKeep,
            Ok(bar) => bar.check_result(&self.state),
        };
        if let Some(parent) = &self.state.parent {
            // inform parent our result
            if let Ok(mut parent_state) = parent.state_mut.lock() {
                parent_state.child_done(self.state.id, result.clone());
            }
        }
        let handle = {
            // scope for printer lock
            let Ok(mut printer) = PRINTER.lock() else {
                return;
            };
            let Some(printer) = printer.as_mut() else {
                return;
            };
            printer.print_bar_done(&result, self.state.parent.is_none());
            printer.take_print_task_if_should_join()
        };
        if let Some(x) = handle {
            let _: Result<(), _> = x.join();
        }
    }
}

/// Internal, immutable state of progress bar
#[derive(Debug)]
pub struct StateImmut {
    /// An ID
    pub id: usize,
    /// Parent of this bar
    pub parent: Option<Arc<ProgressBar>>,
    /// The prefix message (corresponds to message in the builder)
    pub prefix: String,
    /// If percentage field is shown
    pub show_percentage: bool,
    /// If the steps are unbounded
    pub unbounded: bool,
    /// Display the progress using bytes format
    pub display_bytes: bool,
    /// Max number of children to display,
    /// children after the limit will only display one line "... and X more"
    pub max_display_children: usize,
}

/// Internal mutable state
#[derive(Debug)]
pub struct State {
    unreal_total: u64,
    unreal_current: u64,
    message: String,
    /// None means don't keep the progress bar printed
    /// (the default done message is formatted at spawn time)
    done_message: Option<String>,
    /// None means use the default
    interrupted_message: Option<String>,
    eta: Option<Estimater>,
    children: Vec<ChildState>,
}
impl State {
    pub fn new(
        total: u64,
        eta: Option<Estimater>,
        done_message: Option<String>,
        interrupted_message: Option<String>,
    ) -> Self {
        Self {
            unreal_total: total,
            unreal_current: 0,
            message: String::new(),
            done_message,
            interrupted_message,
            eta,
            children: vec![],
        }
    }
    #[inline(always)]
    fn estimate_remaining(
        &mut self,
        unbounded: bool,
        now: &mut Option<Instant>,
        tick: Tick,
    ) -> Option<f32> {
        if unbounded || self.unreal_total == 0 {
            return None;
        }
        self.eta.as_mut()?.update(
            now,
            self.unreal_current.min(self.unreal_total),
            self.unreal_total,
            tick,
        )
    }
    #[inline(always)]
    fn real_current_total(&self, unbounded: bool) -> (u64, Option<u64>) {
        if unbounded {
            (0, None)
        } else if self.unreal_total == 0 {
            // total not known
            (self.unreal_current, None)
        } else {
            (
                self.unreal_current.min(self.unreal_total),
                Some(self.unreal_total),
            )
        }
    }

    pub fn add_child(&mut self, child: &Arc<ProgressBar>) {
        self.children
            .push(ChildState::Progress(child.state.id, Arc::downgrade(child)))
    }

    pub fn child_done(&mut self, child_id: usize, mut result: BarResult) {
        self.children.retain_mut(|child| {
            let ChildState::Progress(id, _) = child else {
                return true;
            };
            if *id != child_id {
                return true;
            }
            match std::mem::take(&mut result) {
                BarResult::DontKeep => false,
                BarResult::Done(message) => {
                    *child = ChildState::Done(message);
                    true
                }
                BarResult::Interrupted(message) => {
                    *child = ChildState::Interrupted(message);
                    true
                }
            }
        });
    }

    pub fn check_result(&self, state: &StateImmut) -> BarResult {
        let is_interrupted = (self.unreal_current == 0 && self.unreal_total == 0)
            || (self.unreal_current < self.unreal_total);
        if !is_interrupted {
            match &self.done_message {
                None => BarResult::DontKeep,
                Some(message) => {
                    let message =
                        self.format_finish_message(message, state.unbounded, state.display_bytes);
                    BarResult::Done(message)
                }
            }
        } else {
            match &self.interrupted_message {
                None => {
                    let message = if state.prefix.is_empty() {
                        self.format_finish_message(
                            "interrupted",
                            state.unbounded,
                            state.display_bytes,
                        )
                    } else {
                        self.format_finish_message(
                            &format!("{}: interrupted", state.prefix),
                            state.unbounded,
                            state.display_bytes,
                        )
                    };
                    BarResult::Interrupted(message)
                }
                Some(message) => {
                    let message =
                        self.format_finish_message(message, state.unbounded, state.display_bytes);
                    BarResult::Interrupted(message)
                }
            }
        }
    }

    pub fn set_message(&mut self, message: &str) {
        self.message.clear();
        self.message.push_str(message);
    }

    pub fn set_done_message(&mut self, message: &str) {
        match &mut self.done_message {
            None => {
                self.done_message = Some(message.to_string());
            }
            Some(msg) => {
                msg.clear();
                msg.push_str(message);
            }
        }
    }

    pub fn set_interrupted_message(&mut self, message: &str) {
        match &mut self.interrupted_message {
            None => {
                self.interrupted_message = Some(message.to_string());
            }
            Some(msg) => {
                msg.clear();
                msg.push_str(message);
            }
        }
    }

    /// Format the bar into the out buffer at the depth
    ///
    /// If depth is 0, the animation character is already formatted.
    /// Otherwise, a "| " should be formatted into the out buffer
    /// at the beginning. The `width` passed in is terminal width minus 2.
    ///
    /// It should also format a new line character into the buffer
    ///
    /// Return number of lines formatted.
    pub fn format_at_depth(
        &mut self,
        depth: usize,
        hierarchy: &mut String,
        fmt: &mut BarFormatter<'_, '_, '_>,
        state: &StateImmut,
    ) -> i32 {
        self.format_self(fmt, fmt.width.saturating_sub((depth + 1) * 2), state);
        fmt.out.push('\n');
        let mut lines = 1;
        // process childrens
        let mut i = 0;
        let mut num_displayed = 0;
        let children_count = self.children.len();
        self.children.retain_mut(|child| {
            let out = &mut *fmt.out;
            let Some(child) = child.upgrade() else {
                i += 1;
                return false; // remove the finished child
            };
            if num_displayed >= state.max_display_children {
                num_displayed += 1;
                return true;
            }
            // format the multi-line syntax
            out.push_str(". ");
            out.push_str(fmt.colors.gray);
            out.push_str(hierarchy);
            if i == children_count - 1 {
                out.push(CHAR_TICK);
                hierarchy.push_str("  ");
            } else {
                out.push(CHAR_BAR_TICK);
                hierarchy.push(CHAR_BAR);
                hierarchy.push(' ');
            }
            out.push(' ');
            let width = fmt.width.saturating_sub((depth + 2) * 2);
            match child {
                ChildStateStrong::Done(message) => {
                    out.push_str(fmt.colors.green);
                    format_message_with_width(out, width, message);
                    out.push('\n');
                    lines += 1;
                    out.push_str(fmt.bar_color);
                }
                ChildStateStrong::Interrupted(message) => {
                    out.push_str(fmt.colors.yellow);
                    format_message_with_width(out, width, message);
                    out.push('\n');
                    lines += 1;
                    out.push_str(fmt.bar_color);
                }
                ChildStateStrong::Progress(child) => {
                    out.push_str(fmt.bar_color);
                    lines += child.format_at_depth(depth + 1, hierarchy, fmt);
                }
            }
            hierarchy.pop();
            hierarchy.pop();
            i += 1;
            num_displayed += 1;
            true
        });
        if num_displayed > state.max_display_children {
            // display the ... and more line
            let out = &mut *fmt.out;
            out.push_str("| ");
            out.push_str(fmt.colors.gray);
            for _ in 0..depth {
                out.push(CHAR_BAR);
                out.push(' ');
            }
            out.push(CHAR_TICK);
            out.push_str(fmt.colors.reset);
            use std::fmt::Write as _;
            let _ = write!(
                out,
                "  ... and {} more",
                num_displayed - state.max_display_children
            );
            out.push_str(fmt.bar_color);
            out.push('\n');
            lines += 1;
        }
        // return number of lines
        lines
    }

    fn format_self(
        &mut self,
        fmt: &mut BarFormatter<'_, '_, '_>,
        mut width: usize,
        state: &StateImmut,
    ) {
        use std::fmt::Write as _;
        let out = &mut *fmt.out;
        let temp = &mut *fmt.temp;

        // not enough width
        match width {
            0 => return,
            1 => {
                out.push('.');
                return;
            }
            2 => {
                out.push_str("..");
                return;
            }
            3 => {
                out.push_str("...");
                return;
            }
            4 => {
                out.push_str("[..]");
                return;
            }
            _ => {}
        }
        let (current, total) = self.real_current_total(state.unbounded);
        // --
        let show_current_total = !state.unbounded;
        let show_prefix = !state.prefix.is_empty();
        // -- :
        let show_percentage = state.show_percentage && total.is_some();
        let eta = self.estimate_remaining(state.unbounded, fmt.now, fmt.tick);
        let show_eta = eta.is_some();
        let show_message = !self.message.is_empty();

        struct Spacing {
            show_separator: bool,
            show_space_before_eta: bool,
            show_space_before_message: bool,
        }

        let spacing = if state.display_bytes {
            Spacing {
                show_separator: show_prefix
                    && (show_current_total || show_percentage || show_eta || show_message),
                show_space_before_eta: show_percentage || show_current_total,
                show_space_before_message: show_percentage || show_current_total || show_eta,
            }
        } else {
            Spacing {
                show_separator: show_prefix && (show_percentage || show_eta || show_message),
                show_space_before_eta: show_percentage,
                show_space_before_message: show_percentage || show_eta,
            }
        };

        if !state.display_bytes && show_current_total {
            temp.clear();
            // _: fmt for string does not fail
            let _ = match total {
                None => write!(temp, "{current}/?"),
                Some(total) => write!(temp, "{current}/{total}"),
            };

            // .len() is safe because / and numbers have the same byte size and width
            // -2 is safe because width > 4 here
            width -= 2;
            out.push('[');
            if temp.len() > width {
                // not enough space
                for _ in 0..width {
                    out.push('.');
                }
                out.push(']');
                return;
            }

            width -= temp.len();
            out.push_str(temp);
            out.push(']');
        }

        if width > 0 {
            out.push(' ');
            width -= 1;
        }

        if show_prefix {
            width = format_message_with_width(out, width, &state.prefix);
        }

        if spacing.show_separator && width > 2 {
            width -= 2;
            out.push_str(": ");
        }

        if state.display_bytes && show_current_total {
            temp.clear();
            // _: fmt for string does not fail
            let _ = match total {
                None => write!(temp, "{}", cu::ByteFormat(current)),
                Some(total) => write!(
                    temp,
                    "{} / {}",
                    cu::ByteFormat(current),
                    cu::ByteFormat(total)
                ),
            };

            if width >= temp.len() {
                width -= temp.len();
                out.push_str(temp);
            }

            if width > 0 {
                out.push(' ');
                width -= 1;
            }
        }

        if show_percentage {
            // unwrap: total is always Some
            let total = total.unwrap();
            if current == total {
                if width >= 4 {
                    width -= 4;
                    out.push_str("100%")
                }
            } else {
                let percentage = current as f32 * 100f32 / total as f32;
                temp.clear();
                // _: fmt for string does not fail
                let _ = write!(temp, "{percentage:.2}%");
                if width >= temp.len() {
                    width -= temp.len();
                    out.push_str(temp);
                }
            }
        }

        if let Some(eta) = eta {
            // ETA SS.SSs
            if spacing.show_space_before_eta && width > 0 {
                out.push(' ');
                width -= 1;
            }
            temp.clear();
            // _: fmt for string does not fail
            let _ = write!(temp, "ETA {eta:.2}s;");
            if width >= temp.len() {
                width -= temp.len();
                out.push_str(temp);
            }
        }

        if show_message {
            if spacing.show_space_before_message && width > 0 {
                out.push(' ');
                width -= 1;
            }
            format_message_with_width(out, width, &self.message);
        }
    }

    fn format_finish_message(&self, message: &str, unbounded: bool, in_bytes: bool) -> String {
        if unbounded {
            return message.to_string();
        }
        let (current, total) = self.real_current_total(unbounded);
        match (total, in_bytes) {
            (None, false) => {
                format!("[{current}/?] {message}")
            }
            (None, true) => {
                let current = cu::ByteFormat(current);
                format!("{message} ({current})")
            }
            (Some(total), false) => {
                format!("[{current}/{total}] {message}")
            }
            (Some(total), true) => {
                let current = cu::ByteFormat(current);
                let total = cu::ByteFormat(total);
                format!("{message} ({current} / {total})")
            }
        }
    }
}

fn format_message_with_width(out: &mut String, mut width: usize, message: &str) -> usize {
    for (c, w) in ansi::with_width(message.chars()) {
        if w > width {
            break;
        }
        width -= w;
        out.push(c);
    }
    width
}