cc-token-usage 3.0.0

use std::fmt::Write as _;

use chrono::{Datelike, NaiveDate};

use crate::analysis::heatmap::HeatmapResult;
use crate::analysis::validate::ValidationReport;
use crate::analysis::wrapped::WrappedResult;
use crate::analysis::{OverviewResult, ProjectResult, SessionResult, TrendResult};
use crate::pricing::calculator::PricingCalculator;

// ─── Helpers ────────────────────────────────────────────────────────────────

fn format_number(n: u64) -> String {
    let s = n.to_string();
    let mut result = String::with_capacity(s.len() + s.len() / 3);
    for (i, ch) in s.chars().rev().enumerate() {
        if i > 0 && i % 3 == 0 {
            result.push(',');
        }
        result.push(ch);
    }
    result.chars().rev().collect()
}

fn format_cost(c: f64) -> String {
    let abs = c.abs();
    let total_cents = (abs * 100.0).round() as u64;
    let whole = total_cents / 100;
    let cents = total_cents % 100;
    let sign = if c < 0.0 { "-" } else { "" };
    format!("{}${}.{:02}", sign, format_number(whole), cents)
}

fn format_duration(minutes: f64) -> String {
    if minutes < 1.0 {
        format!("{:.0}s", minutes * 60.0)
    } else if minutes < 60.0 {
        format!("{:.0}m", minutes)
    } else {
        let h = (minutes / 60.0).floor();
        let m = (minutes % 60.0).round();
        format!("{:.0}h{:.0}m", h, m)
    }
}

// ─── 1. Overview ────────────────────────────────────────────────────────────

pub fn render_overview(result: &OverviewResult, calc: &PricingCalculator) -> String {
    let mut out = String::new();
    let _ = calc;

    let range = result
        .quality
        .time_range
        .map(|(s, e)| {
            let ls = s.with_timezone(&chrono::Local);
            let le = e.with_timezone(&chrono::Local);
            format!("{} ~ {}", ls.format("%Y-%m-%d"), le.format("%Y-%m-%d"))
        })
        .unwrap_or_default();

    writeln!(out, "Claude Code Token Report").unwrap();
    writeln!(out, "{}", range).unwrap();
    writeln!(out).unwrap();

    writeln!(
        out,
        "  {} conversations, {} rounds of back-and-forth",
        format_number(result.total_sessions as u64),
        format_number(result.total_turns as u64)
    )
    .unwrap();
    if result.total_agent_turns > 0 {
        writeln!(
            out,
            "  ({} agent turns, {:.0}% of total)",
            format_number(result.total_agent_turns as u64),
            result.total_agent_turns as f64 / result.total_turns.max(1) as f64 * 100.0
        )
        .unwrap();
    }
    writeln!(out).unwrap();

    writeln!(
        out,
        "  Claude read  {} tokens",
        format_number(result.total_context_tokens)
    )
    .unwrap();
    writeln!(
        out,
        "  Claude wrote {} tokens",
        format_number(result.total_output_tokens)
    )
    .unwrap();
    writeln!(out).unwrap();

    writeln!(
        out,
        "  Cache saved you {} ({:.0}% of reads were free)",
        format_cost(result.cache_savings.total_saved),
        result.cache_savings.savings_pct
    )
    .unwrap();
    writeln!(
        out,
        "  All that would cost {} at API rates",
        format_cost(result.total_cost)
    )
    .unwrap();

    // Subscription value
    if let Some(ref sub) = result.subscription_value {
        writeln!(
            out,
            "  Subscription: {}/mo -> {:.1}x value multiplier",
            format_cost(sub.monthly_price),
            sub.value_multiplier
        )
        .unwrap();
    }

    // Model breakdown
    writeln!(out).unwrap();
    writeln!(
        out,
        "  Model                      Wrote        Rounds     Cost"
    )
    .unwrap();
    writeln!(
        out,
        "  ---------------------------------------------------------"
    )
    .unwrap();

    let mut models: Vec<(&String, &crate::analysis::AggregatedTokens)> =
        result.tokens_by_model.iter().collect();
    models.sort_by(|a, b| {
        let ca = result.cost_by_model.get(a.0).unwrap_or(&0.0);
        let cb = result.cost_by_model.get(b.0).unwrap_or(&0.0);
        cb.partial_cmp(ca).unwrap_or(std::cmp::Ordering::Equal)
    });

    for (model, tokens) in &models {
        let cost = result.cost_by_model.get(*model).unwrap_or(&0.0);
        let short = short_model(model);
        writeln!(
            out,
            "  {:<25} {:>10} {:>9} {:>9}",
            short,
            format_number(tokens.output_tokens),
            format_number(tokens.turns as u64),
            format_cost(*cost)
        )
        .unwrap();
    }

    // Cost by category
    writeln!(out).unwrap();
    let cat = &result.cost_by_category;
    let total = result.total_cost.max(0.001);
    writeln!(out, "  Cost Breakdown").unwrap();
    writeln!(
        out,
        "    Output:      {:>9}  ({:.0}%)",
        format_cost(cat.output_cost),
        cat.output_cost / total * 100.0
    )
    .unwrap();
    writeln!(
        out,
        "    Cache Write: {:>9}  ({:.0}%)",
        format_cost(cat.cache_write_5m_cost + cat.cache_write_1h_cost),
        (cat.cache_write_5m_cost + cat.cache_write_1h_cost) / total * 100.0
    )
    .unwrap();
    writeln!(
        out,
        "    Input:       {:>9}  ({:.0}%)",
        format_cost(cat.input_cost),
        cat.input_cost / total * 100.0
    )
    .unwrap();
    writeln!(
        out,
        "    Cache Read:  {:>9}  ({:.0}%)",
        format_cost(cat.cache_read_cost),
        cat.cache_read_cost / total * 100.0
    )
    .unwrap();

    // Efficiency metrics
    writeln!(out).unwrap();
    writeln!(out, "  Efficiency").unwrap();
    writeln!(
        out,
        "    Output ratio:       {:.2}% ({} output / {} input)",
        result.output_ratio,
        format_number(result.total_output_tokens),
        format_number(result.total_context_tokens)
    )
    .unwrap();
    writeln!(
        out,
        "    Cost per turn:      ${:.3}/turn",
        result.cost_per_turn
    )
    .unwrap();
    writeln!(
        out,
        "    Output per turn:    {} tokens/turn avg",
        format_number(result.tokens_per_output_turn)
    )
    .unwrap();

    // Tool usage top 10
    if !result.tool_counts.is_empty() {
        writeln!(out).unwrap();
        writeln!(out, "  Top Tools").unwrap();
        for (name, count) in result.tool_counts.iter().take(10) {
            let bar_len =
                (*count as f64 / result.tool_counts[0].1.max(1) as f64 * 20.0).round() as usize;
            writeln!(
                out,
                "    {:<18} {:>6}  {}",
                name,
                format_number(*count as u64),
                "█".repeat(bar_len)
            )
            .unwrap();
        }
    }

    // Top 5 projects
    if !result.session_summaries.is_empty() {
        writeln!(out).unwrap();
        writeln!(
            out,
            "  Top Projects                              Sessions   Turns    Cost"
        )
        .unwrap();
        writeln!(
            out,
            "  -------------------------------------------------------------------"
        )
        .unwrap();

        let mut project_map: std::collections::HashMap<&str, (usize, usize, f64)> =
            std::collections::HashMap::new();
        for s in &result.session_summaries {
            let e = project_map.entry(&s.project_display_name).or_default();
            e.0 += 1;
            e.1 += s.turn_count;
            e.2 += s.cost;
        }
        let mut projects: Vec<_> = project_map.into_iter().collect();
        projects.sort_by(|a, b| {
            b.1 .2
                .partial_cmp(&a.1 .2)
                .unwrap_or(std::cmp::Ordering::Equal)
        });

        for (name, (sessions, turns, cost)) in projects.iter().take(5) {
            writeln!(
                out,
                "  {:<40} {:>5} {:>7} {:>9}",
                name,
                sessions,
                turns,
                format_cost(*cost)
            )
            .unwrap();
        }
    }

    // Usage insights
    if !result.session_summaries.is_empty() {
        let summaries = &result.session_summaries;

        // Daily average cost
        if let Some((start, end)) = result.quality.time_range {
            let days = (end - start).num_days().max(1) as f64;
            writeln!(out).unwrap();
            writeln!(
                out,
                "  Daily avg: {} / day  ({} days)",
                format_cost(result.total_cost / days),
                days as u64
            )
            .unwrap();
        }

        // Compaction stats
        let total_compactions: usize = summaries.iter().map(|s| s.compaction_count).sum();
        let sessions_with_compaction = summaries.iter().filter(|s| s.compaction_count > 0).count();
        if total_compactions > 0 {
            writeln!(
                out,
                "  Compactions: {} total across {} sessions",
                total_compactions, sessions_with_compaction
            )
            .unwrap();
        }

        // Max context
        let max_ctx = summaries.iter().map(|s| s.max_context).max().unwrap_or(0);
        if max_ctx > 0 {
            writeln!(out, "  Peak context: {} tokens", format_number(max_ctx)).unwrap();
        }

        // Average session duration
        let durations: Vec<f64> = summaries
            .iter()
            .map(|s| s.duration_minutes)
            .filter(|d| *d > 0.0)
            .collect();
        if !durations.is_empty() {
            let avg_dur = durations.iter().sum::<f64>() / durations.len() as f64;
            writeln!(out, "  Avg session: {}", format_duration(avg_dur)).unwrap();
        }

        // Top 3 most expensive sessions
        let mut by_cost: Vec<&crate::analysis::SessionSummary> = summaries.iter().collect();
        by_cost.sort_by(|a, b| {
            b.cost
                .partial_cmp(&a.cost)
                .unwrap_or(std::cmp::Ordering::Equal)
        });
        writeln!(out).unwrap();
        writeln!(out, "  Most Expensive Sessions").unwrap();
        for s in by_cost.iter().take(3) {
            let dur = format_duration(s.duration_minutes);
            writeln!(
                out,
                "    {} {} {:>5} turns  {}  {}",
                &s.session_id[..s.session_id.len().min(8)],
                truncate_str(&s.project_display_name, 25),
                s.turn_count,
                dur,
                format_cost(s.cost),
            )
            .unwrap();
        }
    }

    // Data quality summary
    writeln!(out).unwrap();
    writeln!(
        out,
        "  Data: {} session files, {} agent files",
        result.quality.total_session_files, result.quality.total_agent_files
    )
    .unwrap();
    if result.quality.orphan_agents > 0 {
        writeln!(
            out,
            "  ({} orphan agents without parent session)",
            result.quality.orphan_agents
        )
        .unwrap();
    }
    // Surface orphan sessions (parent jsonl deleted, subagents still on disk).
    // Their cost / turns / tokens are already included in the totals above —
    // this line just makes the count visible.
    let orphan_session_count = result
        .session_summaries
        .iter()
        .filter(|s| s.is_orphan)
        .count();
    if orphan_session_count > 0 {
        writeln!(
            out,
            "  Orphaned subagents detected: {} (still counted in totals)",
            orphan_session_count
        )
        .unwrap();
    }

    // Pricing fallback warnings — surfaced last so they're not buried.
    if !result.pricing_warnings.is_empty() {
        writeln!(out).unwrap();
        writeln!(
            out,
            "! Pricing fallback ({} unknown model{})",
            result.pricing_warnings.len(),
            if result.pricing_warnings.len() == 1 {
                ""
            } else {
                "s"
            }
        )
        .unwrap();
        for w in &result.pricing_warnings {
            writeln!(
                out,
                "  \u{00b7} {}: {} turns, {} \u{2014} used {} pricing",
                w.unknown_model,
                format_number(w.turn_count),
                format_cost(w.fallback_cost),
                w.fallback_to
            )
            .unwrap();
        }
        writeln!(
            out,
            "  These costs are estimates. Update the pricing table when actual rates are known."
        )
        .unwrap();
    }

    writeln!(out).unwrap();

    out
}

fn short_model(name: &str) -> String {
    let s = name.strip_prefix("claude-").unwrap_or(name);
    if s.len() > 9 {
        let last_dash = s.rfind('-').unwrap_or(s.len());
        let suffix = &s[last_dash + 1..];
        if suffix.len() == 8 && suffix.chars().all(|c| c.is_ascii_digit()) {
            return s[..last_dash].to_string();
        }
    }
    s.to_string()
}

// ─── 2. Projects ────────────────────────────────────────────────────────────

pub fn render_projects(result: &ProjectResult) -> String {
    let mut out = String::new();
    let mut total_cost = 0.0f64;

    writeln!(out, "Projects by Cost").unwrap();
    writeln!(out).unwrap();
    writeln!(out, "  #   Project                          Sessions  Turns  Agent  $/Sess  Model          Cost").unwrap();
    writeln!(out, "  ─────────────────────────────────────────────────────────────────────────────────────────").unwrap();

    for (i, proj) in result.projects.iter().enumerate() {
        let avg_cost = if proj.session_count > 0 {
            proj.cost / proj.session_count as f64
        } else {
            0.0
        };
        let model_short = short_model(&proj.primary_model);
        writeln!(
            out,
            "  {:>2}. {:<30} {:>5}  {:>6}  {:>5}  {:>6}  {:<12}  {:>9}",
            i + 1,
            truncate_str(&proj.display_name, 30),
            proj.session_count,
            proj.total_turns,
            proj.agent_turns,
            format_cost(avg_cost),
            truncate_str(&model_short, 12),
            format_cost(proj.cost),
        )
        .unwrap();
        total_cost += proj.cost;
    }

    writeln!(out).unwrap();
    writeln!(
        out,
        "  Total: {} projects, {}",
        result.projects.len(),
        format_cost(total_cost)
    )
    .unwrap();
    out
}

fn truncate_str(s: &str, max: usize) -> String {
    if s.len() <= max {
        s.to_string()
    } else {
        format!("{}...", &s[..s.floor_char_boundary(max.saturating_sub(3))])
    }
}

// ─── 3. Session ─────────────────────────────────────────────────────────────

pub fn render_session(result: &SessionResult) -> String {
    let mut out = String::new();

    let main_turns = result.turn_details.iter().filter(|t| !t.is_agent).count();

    let orphan_tag = if result.is_orphan { " [orphan]" } else { "" };
    writeln!(
        out,
        "Session {}  {}{}",
        &result.session_id[..result.session_id.len().min(8)],
        result.project,
        orphan_tag
    )
    .unwrap();
    writeln!(out).unwrap();
    writeln!(
        out,
        "  Turns:     {:>6} (+ {} agent)   Duration: {}",
        main_turns,
        result.agent_summary.total_agent_turns,
        format_duration(result.duration_minutes)
    )
    .unwrap();
    writeln!(
        out,
        "  Model:     {:<20}  MaxCtx:   {}",
        result.model,
        format_number(result.max_context)
    )
    .unwrap();
    writeln!(
        out,
        "  CacheHit:  {:>5.1}%                Compacts: {}",
        result.total_tokens.cache_read_tokens as f64
            / result.total_tokens.context_tokens().max(1) as f64
            * 100.0,
        result.compaction_count
    )
    .unwrap();
    writeln!(out, "  Cost:      {}", format_cost(result.total_cost)).unwrap();

    // ── Metadata section ──
    let has_metadata = result.title.is_some()
        || !result.tags.is_empty()
        || result.mode.is_some()
        || !result.git_branches.is_empty()
        || !result.pr_links.is_empty();

    if has_metadata {
        writeln!(out).unwrap();
        writeln!(out, "  ── Metadata ──────────────────────────────────").unwrap();
        if let Some(ref title) = result.title {
            writeln!(out, "  Title:        {}", truncate_str(title, 60)).unwrap();
        }
        if !result.tags.is_empty() {
            writeln!(out, "  Tags:         {}", result.tags.join(", ")).unwrap();
        }
        if let Some(ref mode) = result.mode {
            writeln!(out, "  Mode:         {}", mode).unwrap();
        }
        if !result.git_branches.is_empty() {
            let mut branches: Vec<_> = result.git_branches.iter().collect();
            branches.sort_by(|a, b| b.1.cmp(a.1));
            let parts: Vec<String> = branches
                .iter()
                .map(|(name, count)| format!("{} ({} turns)", name, count))
                .collect();
            writeln!(out, "  Branch:       {}", parts.join(", ")).unwrap();
        }
        for pr in &result.pr_links {
            writeln!(out, "  PR:           {}#{}", pr.repository, pr.number).unwrap();
        }
    }

    // ── Performance section ──
    let has_performance = result.user_prompt_count > 0
        || result.truncated_count > 0
        || result.speculation_accepts > 0
        || !result.service_tiers.is_empty()
        || !result.speeds.is_empty()
        || !result.inference_geos.is_empty()
        || result.api_error_count > 0
        || result.tool_error_count > 0;

    if has_performance {
        writeln!(out).unwrap();
        writeln!(out, "  ── Performance ───────────────────────────────").unwrap();
        if result.user_prompt_count > 0 {
            let total_turns = result.turn_details.len();
            writeln!(
                out,
                "  Autonomy:     1:{:.1} ({} turns / {} user prompts)",
                result.autonomy_ratio, total_turns, result.user_prompt_count
            )
            .unwrap();
        }
        if result.truncated_count > 0 {
            writeln!(
                out,
                "  Truncated:    {} turns hit max_tokens",
                result.truncated_count
            )
            .unwrap();
        }
        if result.api_error_count > 0 || result.tool_error_count > 0 {
            let mut parts = Vec::new();
            if result.api_error_count > 0 {
                parts.push(format!("{} API errors", result.api_error_count));
            }
            if result.tool_error_count > 0 {
                parts.push(format!("{} tool errors", result.tool_error_count));
            }
            writeln!(out, "  Errors:       {}", parts.join(", ")).unwrap();
        }
        if result.speculation_accepts > 0 {
            let saved_secs = result.speculation_time_saved_ms / 1000.0;
            writeln!(
                out,
                "  Speculation:  saved {:.1}s across {} accepts",
                saved_secs, result.speculation_accepts
            )
            .unwrap();
        }
        if !result.service_tiers.is_empty() {
            let total: usize = result.service_tiers.values().sum();
            let mut tiers: Vec<_> = result.service_tiers.iter().collect();
            tiers.sort_by(|a, b| b.1.cmp(a.1));
            let parts: Vec<String> = tiers
                .iter()
                .map(|(name, count)| {
                    format!("{} ({:.0}%)", name, **count as f64 / total as f64 * 100.0)
                })
                .collect();
            writeln!(out, "  Service:      {}", parts.join(", ")).unwrap();
        }
        if !result.speeds.is_empty() {
            let total: usize = result.speeds.values().sum();
            let mut spds: Vec<_> = result.speeds.iter().collect();
            spds.sort_by(|a, b| b.1.cmp(a.1));
            let parts: Vec<String> = spds
                .iter()
                .map(|(name, count)| {
                    format!("{} ({:.0}%)", name, **count as f64 / total as f64 * 100.0)
                })
                .collect();
            writeln!(out, "  Speed:        {}", parts.join(", ")).unwrap();
        }
        if !result.inference_geos.is_empty() {
            let total: usize = result.inference_geos.values().sum();
            let mut geos: Vec<_> = result.inference_geos.iter().collect();
            geos.sort_by(|a, b| b.1.cmp(a.1));
            let parts: Vec<String> = geos
                .iter()
                .map(|(name, count)| {
                    format!("{} ({:.0}%)", name, **count as f64 / total as f64 * 100.0)
                })
                .collect();
            writeln!(out, "  Geo:          {}", parts.join(", ")).unwrap();
        }
    }

    // Per-agent breakdown
    if !result.agent_summary.agents.is_empty() {
        writeln!(out).unwrap();
        writeln!(out, "  Agent Breakdown").unwrap();
        writeln!(
            out,
            "  {:<14} {:<40} {:>6} {:>10} {:>9}",
            "Type", "Description", "Turns", "Output", "Cost"
        )
        .unwrap();
        writeln!(out, "  {}", "-".repeat(83)).unwrap();

        // Main agent line
        let main_turns = result.turn_details.iter().filter(|t| !t.is_agent).count();
        let main_output: u64 = result
            .turn_details
            .iter()
            .filter(|t| !t.is_agent)
            .map(|t| t.output_tokens)
            .sum();
        let main_cost = result.total_cost - result.agent_summary.agent_cost;
        writeln!(
            out,
            "  {:<14} {:<40} {:>6} {:>10} {:>9}",
            "main",
            "(this conversation)",
            main_turns,
            format_number(main_output),
            format_cost(main_cost)
        )
        .unwrap();

        for agent in &result.agent_summary.agents {
            let desc = if agent.description.len() > 40 {
                format!(
                    "{}...",
                    &agent.description[..agent.description.floor_char_boundary(37)]
                )
            } else {
                agent.description.clone()
            };
            writeln!(
                out,
                "  {:<14} {:<40} {:>6} {:>10} {:>9}",
                agent.agent_type,
                desc,
                agent.turns,
                format_number(agent.output_tokens),
                format_cost(agent.cost),
            )
            .unwrap();
        }
    }

    // ── Context Collapse section ──
    if result.collapse_count > 0 {
        writeln!(out).unwrap();
        writeln!(out, "  ── Context Collapse ──────────────────────────").unwrap();

        let risk_warning = if result.collapse_max_risk > 0.5 {
            " \u{26a0}"
        } else {
            ""
        };
        writeln!(
            out,
            "  Collapses:    {} (avg risk: {:.2}, max: {:.2}{})",
            result.collapse_count, result.collapse_avg_risk, result.collapse_max_risk, risk_warning
        )
        .unwrap();

        if !result.collapse_summaries.is_empty() {
            writeln!(out, "  Summaries:").unwrap();
            for (i, summary) in result.collapse_summaries.iter().enumerate() {
                // Determine per-summary risk from snapshot staged spans if available
                // We don't have per-commit risk, so just show the summary text
                // Mark if max_risk > 0.5 for the last entry (heuristic)
                let display = truncate_str(summary, 60);
                writeln!(out, "    {}. \"{}\"", i + 1, display).unwrap();
            }
        }
    }

    // ── Phase 2: session-level capability inventory ──
    // Each row only renders when its data is non-empty (mirrors how metadata
    // rows are gated). Old sessions (pre-2.1.104/2.1.138) emit nothing here.

    // Subagent chips: group by `agent_type` so a session with 7 builder calls
    // renders one chip `builder x 7 ($X.YY)` rather than seven per-agent_id
    // chips. `subagent_types` is empty exactly when `subagents` is.
    if !result.subagent_types.is_empty() {
        let parts: Vec<String> = result
            .subagent_types
            .iter()
            .map(|agg| {
                format!(
                    "{} x {} ({})",
                    agg.agent_type,
                    agg.count,
                    format_cost(agg.total_cost)
                )
            })
            .collect();
        writeln!(out).unwrap();
        writeln!(out, "  Subagents: {}", parts.join(" | ")).unwrap();
    }

    if !result.plugins.is_empty() {
        let parts: Vec<String> = result
            .plugins
            .iter()
            .map(|p| format!("{} ({} turns, {})", p.plugin, p.turns, format_cost(p.cost)))
            .collect();
        writeln!(out, "  Plugins:   {}", parts.join(" | ")).unwrap();
    }

    if !result.skills.is_empty() {
        let parts: Vec<String> = result
            .skills
            .iter()
            .map(|s| format!("{} ({} turns, {})", s.skill, s.turns, format_cost(s.cost)))
            .collect();
        writeln!(out, "  Skills:    {}", parts.join(" | ")).unwrap();
    }

    if !result.hooks.is_empty() {
        let parts: Vec<String> = result
            .hooks
            .iter()
            .map(|h| {
                format!(
                    "{} ({} invocations, {} ms total)",
                    h.command, h.invocations, h.total_duration_ms
                )
            })
            .collect();
        writeln!(out, "  Hooks:     {}", parts.join(" | ")).unwrap();
    }

    // ── Code Attribution section ──
    if let Some(ref attr) = result.attribution {
        writeln!(out).unwrap();
        writeln!(out, "  ── Code Attribution ──────────────────────────").unwrap();
        writeln!(out, "  Files touched:     {}", attr.file_count).unwrap();
        writeln!(
            out,
            "  Claude wrote:      {} chars",
            format_number(attr.total_claude_contribution)
        )
        .unwrap();
        if let Some(prompts) = attr.prompt_count {
            let escape_str = attr
                .escape_count
                .filter(|&e| e > 0)
                .map(|e| format!(" ({} escaped)", e))
                .unwrap_or_default();
            writeln!(out, "  Prompts:           {}{}", prompts, escape_str).unwrap();
        }
        if let Some(perms) = attr.permission_prompt_count {
            if perms > 0 {
                writeln!(out, "  Permissions:       {} prompts shown", perms).unwrap();
            }
        }
    }

    out
}

// ─── 4. Trend ───────────────────────────────────────────────────────────────

pub fn render_trend(result: &TrendResult) -> String {
    let mut out = String::new();
    let mut total_cost = 0.0f64;
    let mut total_turns = 0usize;

    // Find max cost for sparkline scaling
    let max_cost = result.entries.iter().map(|e| e.cost).fold(0.0f64, f64::max);

    writeln!(out, "Usage by {}", result.group_label).unwrap();
    writeln!(out).unwrap();

    for entry in &result.entries {
        // Sparkline bar
        let bar_len = if max_cost > 0.0 {
            (entry.cost / max_cost * 16.0).round() as usize
        } else {
            0
        };
        let bar = "▇".repeat(bar_len);

        // Primary model for this period
        let top_model = entry
            .models
            .iter()
            .max_by_key(|(_, tokens)| *tokens)
            .map(|(m, _)| short_model(m))
            .unwrap_or_default();

        // Cost per turn
        let cpt = if entry.turn_count > 0 {
            entry.cost / entry.turn_count as f64
        } else {
            0.0
        };

        writeln!(
            out,
            "  {:<10}  {:>4} sess  {:>6} turns  {:>9}  ${:.3}/t  {:<12} {}",
            entry.label,
            entry.session_count,
            entry.turn_count,
            format_cost(entry.cost),
            cpt,
            truncate_str(&top_model, 12),
            bar,
        )
        .unwrap();
        total_cost += entry.cost;
        total_turns += entry.turn_count;
    }

    writeln!(out).unwrap();
    let avg_cpt = if total_turns > 0 {
        total_cost / total_turns as f64
    } else {
        0.0
    };
    writeln!(
        out,
        "  Total: {}  ({} turns, avg ${:.3}/turn)",
        format_cost(total_cost),
        format_number(total_turns as u64),
        avg_cpt
    )
    .unwrap();
    out
}

pub fn render_validation(report: &ValidationReport, failures_only: bool) -> String {
    let mut out = String::new();

    writeln!(out, "Token Validation Report").unwrap();
    writeln!(out, "{}", "━".repeat(60)).unwrap();
    writeln!(out).unwrap();

    // Structure checks
    writeln!(out, "Structure Checks:").unwrap();
    for check in &report.structure_checks {
        if failures_only && check.passed {
            continue;
        }
        let status = if check.passed { "OK" } else { "FAIL" };
        if check.passed {
            writeln!(out, "  [{:>4}] {}: {}", status, check.name, check.actual).unwrap();
        } else {
            writeln!(
                out,
                "  [{:>4}] {}: expected={}, actual={}",
                status, check.name, check.expected, check.actual
            )
            .unwrap();
        }
    }
    writeln!(out).unwrap();

    // Per-session results
    let mut fail_sessions = Vec::new();
    for sv in &report.session_results {
        let all_checks: Vec<_> = sv
            .token_checks
            .iter()
            .chain(sv.agent_checks.iter())
            .collect();
        let has_failures = all_checks.iter().any(|c| !c.passed);

        if failures_only && !has_failures {
            continue;
        }

        if has_failures {
            fail_sessions.push(sv);
        }
    }

    if !failures_only {
        writeln!(
            out,
            "Session Validation: {} sessions checked",
            report.session_results.len()
        )
        .unwrap();
        let sessions_ok = report.summary.sessions_passed;
        let sessions_fail = report.summary.sessions_validated - sessions_ok;
        writeln!(out, "  {} PASS, {} FAIL", sessions_ok, sessions_fail).unwrap();
        writeln!(out).unwrap();
    }

    // Show failed sessions in detail
    if !fail_sessions.is_empty() {
        writeln!(out, "Failed Sessions:").unwrap();
        writeln!(out).unwrap();
    }
    for sv in &fail_sessions {
        writeln!(
            out,
            "  Session {}  {}",
            &sv.session_id[..8.min(sv.session_id.len())],
            sv.project
        )
        .unwrap();
        for check in sv.token_checks.iter().chain(sv.agent_checks.iter()) {
            if !check.passed {
                writeln!(
                    out,
                    "    [FAIL] {}: expected={}, actual={}",
                    check.name, check.expected, check.actual
                )
                .unwrap();
            }
        }
        writeln!(out).unwrap();
    }

    // Summary
    writeln!(out, "{}", "━".repeat(60)).unwrap();
    let result_text = if report.summary.failed == 0 {
        "PASS"
    } else {
        "FAIL"
    };
    writeln!(
        out,
        "Result: {} ({}/{} checks passed, {} sessions validated)",
        result_text,
        report.summary.passed,
        report.summary.total_checks,
        report.summary.sessions_validated,
    )
    .unwrap();

    out
}

// ─── 5. Wrapped ────────────────────────────────────────────────────────────

pub fn render_wrapped(result: &WrappedResult) -> String {
    let mut out = String::new();
    let w = 50; // inner width

    // Top border
    writeln!(out, "\u{2554}{}\u{2557}", "\u{2550}".repeat(w)).unwrap();
    let title = format!("Your {} Claude Code Wrapped", result.year);
    let pad = (w.saturating_sub(title.len())) / 2;
    writeln!(
        out,
        "\u{2551}{}{}{}\u{2551}",
        " ".repeat(pad),
        title,
        " ".repeat(w.saturating_sub(pad + title.len()))
    )
    .unwrap();
    writeln!(out, "\u{2560}{}\u{2563}", "\u{2550}".repeat(w)).unwrap();
    writeln!(out).unwrap();

    // Activity
    let active_pct = if result.total_days > 0 {
        result.active_days as f64 / result.total_days as f64 * 100.0
    } else {
        0.0
    };
    writeln!(
        out,
        "  Active Days:      {} / {} ({:.0}%)",
        result.active_days, result.total_days, active_pct
    )
    .unwrap();
    writeln!(out, "  Longest Streak:   {} days", result.longest_streak).unwrap();
    writeln!(out, "  Ghost Days:       {}", result.ghost_days).unwrap();
    writeln!(out).unwrap();

    // Volume
    writeln!(
        out,
        "  {} sessions, {} turns",
        format_number(result.total_sessions as u64),
        format_number(result.total_turns as u64)
    )
    .unwrap();
    if result.total_agent_turns > 0 {
        let agent_pct = result.total_agent_turns as f64 / result.total_turns.max(1) as f64 * 100.0;
        writeln!(
            out,
            "  {} agent turns ({:.0}% autonomous)",
            format_number(result.total_agent_turns as u64),
            agent_pct
        )
        .unwrap();
    }
    writeln!(out, "  {} API equivalent", format_cost(result.total_cost)).unwrap();
    writeln!(out).unwrap();

    // Archetype
    writeln!(
        out,
        "  Developer Archetype: \"{}\"",
        result.archetype.label()
    )
    .unwrap();
    writeln!(out, "  {}", result.archetype.description()).unwrap();
    writeln!(out).unwrap();

    // Peak patterns
    writeln!(
        out,
        "  Peak Hour:    {:02}:00-{:02}:00",
        result.peak_hour,
        (result.peak_hour + 1) % 24
    )
    .unwrap();
    writeln!(out, "  Peak Day:     {}", result.peak_weekday).unwrap();
    writeln!(out).unwrap();

    // Efficiency
    if result.autonomy_ratio > 0.0 {
        writeln!(
            out,
            "  Autonomy:     1:{:.1} (turns per user prompt)",
            result.autonomy_ratio
        )
        .unwrap();
    }
    if result.avg_session_duration_min > 0.0 {
        writeln!(
            out,
            "  Avg Session:  {}",
            format_duration(result.avg_session_duration_min)
        )
        .unwrap();
    }
    writeln!(
        out,
        "  Avg Cost:     {}/session",
        format_cost(result.avg_cost_per_session)
    )
    .unwrap();
    writeln!(out).unwrap();

    // Top Tools
    if !result.top_tools.is_empty() {
        writeln!(out, "  Top Tools").unwrap();
        let max_count = result.top_tools.first().map(|(_, c)| *c).unwrap_or(1);
        for (name, count) in &result.top_tools {
            let bar_len = (*count as f64 / max_count.max(1) as f64 * 20.0).round() as usize;
            writeln!(
                out,
                "    {:<18} {:>6}  {}",
                name,
                format_number(*count as u64),
                "\u{2588}".repeat(bar_len)
            )
            .unwrap();
        }
        writeln!(out).unwrap();
    }

    // Top Projects
    if !result.top_projects.is_empty() {
        writeln!(out, "  Top Projects").unwrap();
        for (name, cost) in &result.top_projects {
            writeln!(
                out,
                "    {:<30} {}",
                truncate_str(name, 30),
                format_cost(*cost)
            )
            .unwrap();
        }
        writeln!(out).unwrap();
    }

    // Most Expensive Session
    if let Some((ref id, cost, ref project)) = result.most_expensive_session {
        writeln!(out, "  Most Expensive Session").unwrap();
        let short_id = if id.len() > 8 { &id[..8] } else { id };
        writeln!(
            out,
            "    {}  {}  {}",
            short_id,
            truncate_str(project, 25),
            format_cost(cost)
        )
        .unwrap();
        writeln!(out).unwrap();
    }

    // Longest Session
    if let Some((ref id, dur_min, ref project)) = result.longest_session {
        if dur_min > 0.0 {
            writeln!(out, "  Longest Session").unwrap();
            let short_id = if id.len() > 8 { &id[..8] } else { id };
            writeln!(
                out,
                "    {}  {}  {}",
                short_id,
                truncate_str(project, 25),
                format_duration(dur_min)
            )
            .unwrap();
            writeln!(out).unwrap();
        }
    }

    // Model distribution
    if !result.model_distribution.is_empty() {
        writeln!(out, "  Models").unwrap();
        for (model, turns) in &result.model_distribution {
            let short = short_model(model);
            let pct = *turns as f64 / result.total_turns.max(1) as f64 * 100.0;
            writeln!(
                out,
                "    {:<25} {:>6} turns ({:.0}%)",
                short,
                format_number(*turns as u64),
                pct
            )
            .unwrap();
        }
        writeln!(out).unwrap();
    }

    // Metadata footer
    let mut meta_lines: Vec<String> = Vec::new();
    if result.total_speculation_time_saved_ms > 0.0 {
        let saved_sec = result.total_speculation_time_saved_ms / 1000.0;
        if saved_sec >= 60.0 {
            meta_lines.push(format!(
                "  Speculation saved you {:.1} minutes",
                saved_sec / 60.0
            ));
        } else {
            meta_lines.push(format!("  Speculation saved you {:.1} seconds", saved_sec));
        }
    }
    if result.total_pr_count > 0 {
        meta_lines.push(format!(
            "  {} PRs shipped via Claude Code",
            result.total_pr_count
        ));
    }
    if result.total_collapse_count > 0 {
        meta_lines.push(format!(
            "  {} context collapses",
            result.total_collapse_count
        ));
    }
    if !meta_lines.is_empty() {
        for line in &meta_lines {
            writeln!(out, "{}", line).unwrap();
        }
        writeln!(out).unwrap();
    }

    // Bottom border
    writeln!(out, "\u{255a}{}\u{255d}", "\u{2550}".repeat(w)).unwrap();

    out
}

// ─── 6. Heatmap ────────────────────────────────────────────────────────────

pub fn render_heatmap(result: &HeatmapResult) -> String {
    let mut out = String::new();
    let (p25, p50, p75) = result.thresholds;

    writeln!(out, "Activity Heatmap").unwrap();
    writeln!(
        out,
        "{}  ~  {}",
        result.start_date.format("%Y-%m-%d"),
        result.end_date.format("%Y-%m-%d")
    )
    .unwrap();
    writeln!(out).unwrap();

    // Map turns to glyph
    let glyph = |turns: usize| -> char {
        if turns == 0 {
            '\u{00B7}' // middle dot for zero
        } else if turns < p25 {
            '\u{2591}' // light shade
        } else if turns < p50 {
            '\u{2592}' // medium shade
        } else if turns < p75 {
            '\u{2593}' // dark shade
        } else {
            '\u{2588}' // full block
        }
    };

    // Build the calendar grid.
    // Columns = weeks, rows = weekdays (Mon=0 .. Sun=6).
    // Find the Monday on or before start_date to align the grid.
    let start_weekday = result.start_date.weekday().num_days_from_monday(); // 0=Mon
    let grid_start = result.start_date - chrono::Duration::days(start_weekday as i64);

    // End at the Sunday on or after end_date
    let end_weekday = result.end_date.weekday().num_days_from_monday();
    let grid_end = result.end_date + chrono::Duration::days((6 - end_weekday) as i64);

    let total_days = (grid_end - grid_start).num_days() as usize + 1;
    let num_weeks = total_days.div_ceil(7);

    // Build a lookup from date -> turns
    let mut turns_by_date: std::collections::HashMap<NaiveDate, usize> =
        std::collections::HashMap::new();
    for d in &result.daily {
        turns_by_date.insert(d.date, d.turns);
    }

    // Render month labels on top.
    // Each week column is 1 char wide. Month labels ("Jan", etc.) are 3 chars.
    // A label is placed at the week column containing the 1st of that month.
    // Labels that would overlap a previous label are skipped.
    let label_width = 5; // "Mon  " prefix width

    // Collect (week_index, month_abbr) for each month that has its 1st within the grid
    let mut month_marks: Vec<(usize, &str)> = Vec::new();
    {
        // Walk from the first month that starts on or after grid_start
        let mut d = if grid_start.day() == 1 {
            grid_start
        } else {
            // Advance to the 1st of the next month
            let (y, m) = if grid_start.month() == 12 {
                (grid_start.year() + 1, 1)
            } else {
                (grid_start.year(), grid_start.month() + 1)
            };
            NaiveDate::from_ymd_opt(y, m, 1).unwrap_or(grid_start)
        };

        while d <= grid_end {
            let week_idx = ((d - grid_start).num_days() / 7) as usize;
            month_marks.push((week_idx, month_abbr(d.month())));
            // Advance to the 1st of the next month
            d = if d.month() == 12 {
                NaiveDate::from_ymd_opt(d.year() + 1, 1, 1).unwrap()
            } else {
                NaiveDate::from_ymd_opt(d.year(), d.month() + 1, 1).unwrap()
            };
        }
    }

    // Build the header string by placing labels at correct column positions
    let mut month_header = " ".repeat(label_width);
    let mut cursor = 0usize; // tracks how many week-columns we have filled
    for (col, name) in &month_marks {
        if *col >= cursor {
            // Pad with spaces from cursor to this column
            for _ in cursor..*col {
                month_header.push(' ');
            }
            month_header.push_str(name);
            cursor = col + name.len(); // name takes 3 column slots
        }
        // else: skip this label (overlaps with previous)
    }
    writeln!(out, "{}", month_header.trim_end()).unwrap();

    // Render each weekday row (show Mon, Wed, Fri, Sun labels; blank for others)
    let weekday_labels = ["Mon", "   ", "Wed", "   ", "Fri", "   ", "Sun"];

    for row in 0..7u32 {
        let label = weekday_labels[row as usize];
        write!(out, "{:<5}", label).unwrap();

        for week_idx in 0..num_weeks {
            let day = grid_start + chrono::Duration::days((week_idx * 7 + row as usize) as i64);
            if day < result.start_date || day > result.end_date {
                write!(out, " ").unwrap();
            } else {
                let turns = turns_by_date.get(&day).copied().unwrap_or(0);
                write!(out, "{}", glyph(turns)).unwrap();
            }
        }
        writeln!(out).unwrap();
    }

    // Legend
    writeln!(out).unwrap();
    writeln!(
        out,
        "     \u{00B7}=0  \u{2591}<P25({})  \u{2592}<P50({})  \u{2593}<P75({})  \u{2588}\u{2265}P75",
        p25, p50, p75
    )
    .unwrap();

    // Stats
    writeln!(out).unwrap();
    writeln!(
        out,
        "  Active days:     {}/{}",
        result.stats.active_days, result.stats.total_days
    )
    .unwrap();
    writeln!(
        out,
        "  Current streak:  {} days",
        result.stats.current_streak
    )
    .unwrap();
    writeln!(
        out,
        "  Longest streak:  {} days",
        result.stats.longest_streak
    )
    .unwrap();

    if let Some((date, turns)) = result.stats.busiest_day {
        writeln!(
            out,
            "  Busiest day:     {} ({} turns)",
            date.format("%Y-%m-%d"),
            turns
        )
        .unwrap();
    }

    writeln!(out).unwrap();

    out
}

fn month_abbr(m: u32) -> &'static str {
    match m {
        1 => "Jan",
        2 => "Feb",
        3 => "Mar",
        4 => "Apr",
        5 => "May",
        6 => "Jun",
        7 => "Jul",
        8 => "Aug",
        9 => "Sep",
        10 => "Oct",
        11 => "Nov",
        12 => "Dec",
        _ => "???",
    }
}

// ─── Tests ──────────────────────────────────────────────────────────────────

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_format_number() {
        assert_eq!(format_number(0), "0");
        assert_eq!(format_number(999), "999");
        assert_eq!(format_number(1_000), "1,000");
        assert_eq!(format_number(1_234_567), "1,234,567");
    }

    #[test]
    fn test_format_cost() {
        assert_eq!(format_cost(0.0), "$0.00");
        assert_eq!(format_cost(1.5), "$1.50");
        assert_eq!(format_cost(1234.56), "$1,234.56");
    }
}