//! 开发工具画面的绘制辅助：文字行、按钮、分隔线和滚动条。
//! 绘制命令与可交互区域同步登记，保证屏幕上的管理控件能用同一几何命中。
//!
use super::*;

/// 开发工具的绘制助手，把布局结果写入同帧显示列表。
pub(super) struct Painter {
    pub(super) ui: Ui<Action>,
    pub(super) layout: DeveloperToolsLayout,
}
impl Painter {
    /// 绘制对应管理界面原语，并按控件需要同步登记命中和滚动区域。
    pub(super) fn fill(&mut self, r: Rect, c: Color) {
        self.ui.fill(r, c);
    }
    /// 绘制对应管理界面原语，并按控件需要同步登记命中和滚动区域。
    pub(super) fn label(&mut self, x: f32, y: f32, value: &str, c: Color, code: bool) {
        self.ui.label(x, y, value, c, code);
    }
    /// 绘制对应管理界面原语，并按控件需要同步登记命中和滚动区域。
    pub(super) fn button(&mut self, r: Rect, label: &str, action: Action, active: bool) {
        let role = match action {
            Action::Follow | Action::Snapshot | Action::Cloud => Role::Toggle,
            _ => Role::Button,
        };
        self.ui
            .button(r, action, Button::new(label).selected(active).role(role));
    }
    /// 绘制对应管理界面原语，并按控件需要同步登记命中和滚动区域。
    pub(super) fn enabled_button(&mut self, r: Rect, label: &str, action: Action, enabled: bool) {
        self.ui
            .button(r, action, Button::new(label).enabled(enabled));
    }
    /// 绘制对应管理界面原语，并按控件需要同步登记命中和滚动区域。
    pub(super) fn split(&mut self, r: Rect, kind: Split) {
        // Paint and register splitters after all pane content, in one overlay pass.
        self.layout.splits.push((r, kind));
    }
    /// 绘制对应管理界面原语，并按控件需要同步登记命中和滚动区域。
    pub(super) fn lines(
        &mut self,
        area: Rect,
        region: Region,
        lines: &[Line],
        state: &mut DeveloperToolsState,
        follow: bool,
    ) {
        let content_h = lines.len() as f32 * ROW + 12.0;
        use std::hash::{Hash, Hasher};
        let mut hash = std::collections::hash_map::DefaultHasher::new();
        for line in lines {
            line.value.hash(&mut hash);
        }
        let fingerprint = hash.finish();
        let cache = &mut state.widths[region as usize];
        let content_w = match *cache {
            Some((previous, width)) if previous == fingerprint => width,
            _ => {
                let width = lines
                    .iter()
                    .map(|line| text::measure(&line.value, TextStyle::code()).width + 20.0)
                    .fold(0.0_f32, f32::max);
                *cache = Some((fingerprint, width));
                width
            }
        };
        let s = &mut state.scroll[region as usize];
        s.y = if follow {
            (content_h - area.height + 12.0).max(0.0)
        } else {
            s.y.clamp(0.0, (content_h - area.height + 12.0).max(0.0))
        };
        s.x = s.x.clamp(0.0, (content_w - area.width + 12.0).max(0.0));
        self.ui.list.push(DrawCommand::PushClip(Rect::new(
            area.x,
            area.y,
            (area.width - 9.0).max(0.0),
            (area.height - 9.0).max(0.0),
        )));
        if region == Region::Source {
            let values = lines
                .iter()
                .map(|line| line.value.chars().skip(7).collect::<String>())
                .collect::<Vec<_>>();
            state.source_selection.set_lines(&values);
            self.layout.source = Some((
                area,
                Point::new(
                    area.x + 8.0 - s.x + text::measure("       ", TextStyle::code()).width,
                    area.y + 5.0 - s.y,
                ),
                values,
            ));
        }
        let first = (s.y / ROW).floor() as usize;
        let count = (area.height / ROW).ceil() as usize + 2;
        for (i, line) in lines.iter().enumerate().skip(first).take(count) {
            let y = area.y + 5.0 + i as f32 * ROW - s.y;
            if let Some(divider) = line.divider {
                self.fill(
                    Rect::new(area.x, y, area.width, 1.0),
                    match divider {
                        Divider::Accent => self.ui.theme.accent,
                        Divider::Neutral => BORDER,
                    },
                );
            }
            let paint = Rect::new(area.x, y, area.width, ROW);
            if let Some(action) = &line.action {
                let top = y.max(area.y);
                let bottom = (y + ROW).min(area.y + area.height - 9.0);
                if bottom > top {
                    self.ui.row(
                        paint,
                        Rect::new(area.x, top, area.width - 9.0, bottom - top),
                        action.clone(),
                        line.selected,
                    );
                }
            } else if line.selected {
                self.fill(paint, self.ui.theme.soft());
            }
            if region == Region::Source
                && let Some((_, origin, values)) = &self.layout.source
                && let Some((left, right)) = state.source_selection.span(
                    i,
                    state.selection && state.focus == Some(Focus::Source),
                    values,
                )
            {
                self.fill(
                    Rect::new(origin.x + left, y, right - left, ROW),
                    self.ui.theme.hover(),
                );
            }
            self.label(area.x + 8.0 - s.x, y, &line.value, line.color, true);
        }
        self.ui.list.push(DrawCommand::PopClip);
        self.layout
            .regions
            .push((area, region, content_w, content_h));
        self.scrollbar(area, region, false, s.y, content_h);
        self.scrollbar(area, region, true, s.x, content_w);
    }
    /// 绘制对应管理界面原语，并按控件需要同步登记命中和滚动区域。
    pub(super) fn scrollbar(
        &mut self,
        r: Rect,
        region: Region,
        h: bool,
        offset: f32,
        content: f32,
    ) {
        let viewport = if h { r.width } else { r.height } - 10.0;
        if content <= viewport || viewport <= 0.0 {
            return;
        }
        let length = (viewport * viewport / content).max(24.0).min(viewport);
        let travel = (viewport - length).max(1.0);
        let maximum = (content - viewport).max(1.0);
        let position = (offset / maximum).clamp(0.0, 1.0) * travel;
        let track = if h {
            Rect::new(r.x, r.y + r.height - 8.0, viewport, 8.0)
        } else {
            Rect::new(r.x + r.width - 8.0, r.y, 8.0, viewport)
        };
        self.fill(track, BAR);
        let thumb = if h {
            Rect::new(track.x + position, track.y + 1.0, length, 6.0)
        } else {
            Rect::new(track.x + 1.0, track.y + position, 6.0, length)
        };
        self.ui.scrollbar(
            thumb,
            WidgetId::new(("scroll", region, h)),
            if h { Axis::Horizontal } else { Axis::Vertical },
        );
        self.layout
            .thumbs
            .push((thumb, region, h, maximum / travel));
    }
}
#[derive(Clone)]
/// 一行可绘制、可关联源码位置的工具文本。
pub(super) struct Line {
    pub(super) value: String,
    pub(super) color: Color,
    pub(super) divider: Option<Divider>,
    pub(super) selected: bool,
    pub(super) action: Option<Action>,
}
#[derive(Clone, Copy)]
/// 管理画面内分隔条方向/位置描述。
pub(super) enum Divider {
    Accent,
    Neutral,
}
impl Line {
    /// 构造本类型并初始化其状态；资源建立和默认字段以函数体为准。
    pub(super) fn new(value: impl Into<String>, color: Color) -> Self {
        Self {
            value: value.into(),
            color,
            divider: None,
            selected: false,
            action: None,
        }
    }
}
/// 按行绘制工具文本，返回后续布局需要的占用范围。
pub(super) fn multiline(out: &mut Vec<Line>, value: &str, color: Color) {
    out.extend(
        value
            .replace('\t', "    ")
            .split('\n')
            .map(|s| Line::new(s, color)),
    );
}
/// 把一条 Console 结果投影为可滚动、可选择的文字画面。
pub(super) fn console_result(out: &mut Vec<Line>, body: &str, color: Color) {
    if let Ok(value) = serde_json::from_str::<serde_json::Value>(body) {
        if value["execution"] == "repl" {
            out.push(Line::new(
                if value["rendered"] == true {
                    format!(
                        "Rendered revision {} · session {}",
                        value["revision"], value["session"]
                    )
                } else {
                    format!(
                        "Session {} · retained in memory; page unchanged",
                        value["session"]
                    )
                },
                MUTED,
            ));
        }
        if value["session_reset"] == true {
            multiline(
                out,
                value["message"]
                    .as_str()
                    .or(value["error"].as_str())
                    .unwrap_or("Session reset"),
                color,
            );
            return;
        }
        if let Some(result) = value["value"].as_str() {
            multiline(out, result, color);
            return;
        }
        if let Some(diagnostics) = value["diagnostics"].as_array()
            && !diagnostics.is_empty()
        {
            for d in diagnostics {
                if let Some(line) = d["line"].as_u64() {
                    out.push(Line::new(
                        format!("Error · line {line}, column {}", d["column"]),
                        color,
                    ));
                }
                multiline(
                    out,
                    d["message"].as_str().unwrap_or("Execution failed"),
                    color,
                );
            }
            return;
        }
        if let Some(error) = value["error"].as_str() {
            multiline(out, error, color);
            return;
        }
        if let Some(revision) = value["revision"].as_u64() {
            out.push(Line::new(format!("Committed revision {revision}"), color));
            return;
        }
    }
    multiline(out, body, color);
}
/// 将代码层次展开为工具可绘制的行数据，保留节点与源范围关联。
pub(super) fn flatten<'a>(node: &'a CodeNode, depth: usize, out: &mut Vec<(usize, &'a CodeNode)>) {
    out.push((depth, node));
    for child in &node.children {
        flatten(child, depth + 1, out);
    }
}

/// 绘制选中请求的头部、正文预览与响应信息，不重新执行该请求。
pub(super) fn request_details(out: &mut Vec<Line>, r: &Exchange) {
    multiline(
        out,
        &format!(
            "#{}  {} {}\n{} · {} · {} ms\nStatus: {}",
            r.id,
            r.method,
            r.path,
            r.timestamp,
            r.origin,
            r.elapsed_ms,
            r.status.map_or("pending".into(), |s| s.to_string())
        ),
        TEXT,
    );
    for (title, body) in [
        ("REQUEST HEADERS", &r.request_headers),
        ("REQUEST BODY", &r.request),
        ("RESPONSE HEADERS", &r.response_headers),
        ("RESPONSE BODY", &r.response),
    ] {
        out.push(Line::new("", MUTED));
        let mut l = Line::new(title, MUTED);
        l.divider = Some(Divider::Accent);
        out.push(l);
        multiline(
            out,
            if body.is_empty() { "(empty)" } else { body },
            if title == "RESPONSE BODY" && r.status.is_some_and(|s| s >= 400) {
                ERROR
            } else {
                TEXT
            },
        );
    }
}