pub mod flex;
pub mod justify;
pub mod priority;

use crate::config::{Config, JustifyMode, LayoutValue, SectionBase};
use crate::format;
use crate::section::{self, RenderContext, SectionOutput};

/// A section that survived priority drops and has rendered output.
pub struct ActiveSection {
    pub id: String,
    pub output: SectionOutput,
    pub priority: u8,
    pub is_spacer: bool,
    pub is_flex: bool,
}

/// Resolve layout: preset lookup with optional responsive override.
pub fn resolve_layout(config: &Config, term_width: u16) -> Vec<Vec<String>> {
    match &config.layout {
        LayoutValue::Preset(name) => {
            let effective = if config.global.responsive {
                responsive_preset(term_width, &config.global.breakpoints)
            } else {
                name.as_str()
            };
            config
                .presets
                .get(effective)
                .or_else(|| config.presets.get(name.as_str()))
                .cloned()
                .unwrap_or_else(|| vec![vec!["model".into(), "project".into()]])
        }
        LayoutValue::Custom(lines) => lines.clone(),
    }
}

fn responsive_preset(width: u16, bp: &crate::config::Breakpoints) -> &'static str {
    if width < bp.narrow {
        "dense"
    } else if width < bp.medium {
        "standard"
    } else {
        "verbose"
    }
}

/// Full render: resolve layout, render each line, join with newlines.
pub fn render_all(ctx: &RenderContext) -> String {
    let layout = resolve_layout(ctx.config, ctx.term_width);
    let separator = &ctx.config.global.separator;

    let lines: Vec<String> = layout
        .iter()
        .filter_map(|line_ids| render_line(line_ids, ctx, separator))
        .collect();

    lines.join("\n")
}

/// Render a single layout line.
/// Three phases: render all -> priority drop -> flex/justify.
fn render_line(section_ids: &[String], ctx: &RenderContext, separator: &str) -> Option<String> {
    // Phase 1: Render all sections, collect active ones
    let mut active: Vec<ActiveSection> = Vec::new();

    for id in section_ids {
        if let Some(mut output) = section::render_section(id, ctx) {
            if output.raw.is_empty() && !section::is_spacer(id) {
                continue;
            }

            // Apply per-section formatting (prefix, suffix, color override, pad, align)
            if let Some(base) = section_base(id, ctx.config) {
                format::apply_formatting(
                    &mut output.raw,
                    &mut output.ansi,
                    base,
                    ctx.theme,
                    &ctx.config.colors,
                );
            }

            let (prio, is_flex) = section_meta(id, ctx.config);
            active.push(ActiveSection {
                id: id.clone(),
                output,
                priority: prio,
                is_spacer: section::is_spacer(id),
                is_flex,
            });
        }
    }

    if active.is_empty() || active.iter().all(|s| s.is_spacer) {
        return None;
    }

    // Phase 2: Priority drop if overflowing
    let mut active = priority::priority_drop(active, ctx.term_width, separator);

    // Phase 3: Flex expand or justify
    let line = if ctx.config.global.justify != JustifyMode::Left
        && !active.iter().any(|s| s.is_spacer)
        && active.len() > 1
    {
        justify::justify(
            &active,
            ctx.term_width,
            separator,
            ctx.config.global.justify,
        )
    } else {
        flex::flex_expand(&mut active, ctx, separator);
        assemble_left(&active, separator, ctx.color_enabled)
    };

    Some(line)
}

/// Left-aligned assembly with separator dimming and spacer suppression.
fn assemble_left(active: &[ActiveSection], separator: &str, color_enabled: bool) -> String {
    let mut output = String::new();
    let mut prev_is_spacer = false;

    for (i, sec) in active.iter().enumerate() {
        if i > 0 && !prev_is_spacer && !sec.is_spacer {
            if color_enabled {
                output.push_str(&format!(
                    "{}{separator}{}",
                    crate::color::DIM,
                    crate::color::RESET
                ));
            } else {
                output.push_str(separator);
            }
        }
        output.push_str(&sec.output.ansi);
        prev_is_spacer = sec.is_spacer;
    }

    output
}

/// Look up section priority and flex from config.
fn section_meta(id: &str, config: &Config) -> (u8, bool) {
    if section::is_spacer(id) {
        return (1, true);
    }

    macro_rules! meta_base {
        ($section:expr) => {
            ($section.priority, $section.flex)
        };
    }
    macro_rules! meta_flat {
        ($section:expr) => {
            ($section.base.priority, $section.base.flex)
        };
    }

    match id {
        "model" => meta_base!(config.sections.model),
        "provider" => meta_base!(config.sections.provider),
        "project" => meta_flat!(config.sections.project),
        "vcs" => meta_flat!(config.sections.vcs),
        "beads" => meta_flat!(config.sections.beads),
        "context_bar" => meta_flat!(config.sections.context_bar),
        "context_usage" => meta_flat!(config.sections.context_usage),
        "context_remaining" => meta_flat!(config.sections.context_remaining),
        "tokens_raw" => meta_flat!(config.sections.tokens_raw),
        "cache_efficiency" => meta_base!(config.sections.cache_efficiency),
        "cost" => meta_flat!(config.sections.cost),
        "cost_velocity" => meta_base!(config.sections.cost_velocity),
        "token_velocity" => meta_base!(config.sections.token_velocity),
        "cost_trend" => meta_flat!(config.sections.cost_trend),
        "context_trend" => meta_flat!(config.sections.context_trend),
        "lines_changed" => meta_base!(config.sections.lines_changed),
        "duration" => meta_base!(config.sections.duration),
        "tools" => meta_flat!(config.sections.tools),
        "turns" => meta_flat!(config.sections.turns),
        "load" => meta_flat!(config.sections.load),
        "version" => meta_base!(config.sections.version),
        "time" => meta_flat!(config.sections.time),
        "output_style" => meta_base!(config.sections.output_style),
        "hostname" => meta_base!(config.sections.hostname),
        _ => (2, false), // custom sections default
    }
}

/// Look up the SectionBase for a given section ID.
/// Returns None for spacers and unknown custom sections.
fn section_base<'a>(id: &str, config: &'a Config) -> Option<&'a SectionBase> {
    match id {
        "model" => Some(&config.sections.model),
        "provider" => Some(&config.sections.provider),
        "project" => Some(&config.sections.project.base),
        "vcs" => Some(&config.sections.vcs.base),
        "beads" => Some(&config.sections.beads.base),
        "context_bar" => Some(&config.sections.context_bar.base),
        "context_usage" => Some(&config.sections.context_usage.base),
        "context_remaining" => Some(&config.sections.context_remaining.base),
        "tokens_raw" => Some(&config.sections.tokens_raw.base),
        "cache_efficiency" => Some(&config.sections.cache_efficiency),
        "cost" => Some(&config.sections.cost.base),
        "cost_velocity" => Some(&config.sections.cost_velocity),
        "token_velocity" => Some(&config.sections.token_velocity),
        "cost_trend" => Some(&config.sections.cost_trend.base),
        "context_trend" => Some(&config.sections.context_trend.base),
        "lines_changed" => Some(&config.sections.lines_changed),
        "duration" => Some(&config.sections.duration),
        "tools" => Some(&config.sections.tools.base),
        "turns" => Some(&config.sections.turns.base),
        "load" => Some(&config.sections.load.base),
        "version" => Some(&config.sections.version),
        "time" => Some(&config.sections.time.base),
        "output_style" => Some(&config.sections.output_style),
        "hostname" => Some(&config.sections.hostname),
        _ => None,
    }
}