const std = @import("std");
const vaxis = @import("vaxis");
const zfin = @import("../root.zig");
const fmt = @import("../format.zig");
const theme_mod = @import("theme.zig");
const tui = @import("../tui.zig");
const App = tui.App;
const StyledLine = tui.StyledLine;

// ── Data loading ──────────────────────────────────────────────

pub fn loadData(app: *App) void {
    app.analysis_loaded = true;

    // Ensure portfolio is loaded first
    if (!app.portfolio_loaded) app.loadPortfolioData();
    const pf = app.portfolio orelse return;
    const summary = app.portfolio_summary orelse return;

    // Load classification metadata file
    if (app.classification_map == null) {
        // Look for metadata.srf next to the portfolio file
        if (app.portfolio_path) |ppath| {
            // Derive metadata path: same directory as portfolio, named "metadata.srf"
            const dir_end = if (std.mem.lastIndexOfScalar(u8, ppath, std.fs.path.sep)) |idx| idx + 1 else 0;
            const meta_path = std.fmt.allocPrint(app.allocator, "{s}metadata.srf", .{ppath[0..dir_end]}) catch return;
            defer app.allocator.free(meta_path);

            const file_data = std.fs.cwd().readFileAlloc(app.allocator, meta_path, 1024 * 1024) catch {
                app.setStatus("No metadata.srf found. Run: zfin enrich <portfolio.srf> > metadata.srf");
                return;
            };
            defer app.allocator.free(file_data);

            app.classification_map = zfin.classification.parseClassificationFile(app.allocator, file_data) catch {
                app.setStatus("Error parsing metadata.srf");
                return;
            };
        }
    }

    // Load account tax type metadata file (optional)
    if (app.account_map == null) {
        if (app.portfolio_path) |ppath| {
            const dir_end = if (std.mem.lastIndexOfScalar(u8, ppath, std.fs.path.sep)) |idx| idx + 1 else 0;
            const acct_path = std.fmt.allocPrint(app.allocator, "{s}accounts.srf", .{ppath[0..dir_end]}) catch {
                loadDataFinish(app, pf, summary);
                return;
            };
            defer app.allocator.free(acct_path);

            if (std.fs.cwd().readFileAlloc(app.allocator, acct_path, 1024 * 1024)) |acct_data| {
                defer app.allocator.free(acct_data);
                app.account_map = zfin.analysis.parseAccountsFile(app.allocator, acct_data) catch null;
            } else |_| {
                // accounts.srf is optional -- analysis works without it
            }
        }
    }

    loadDataFinish(app, pf, summary);
}

fn loadDataFinish(app: *App, pf: zfin.Portfolio, summary: zfin.valuation.PortfolioSummary) void {
    const cm = app.classification_map orelse {
        app.setStatus("No classification data. Run: zfin enrich <portfolio.srf> > metadata.srf");
        return;
    };

    // Free previous result
    if (app.analysis_result) |*ar| ar.deinit(app.allocator);

    app.analysis_result = zfin.analysis.analyzePortfolio(
        app.allocator,
        summary.allocations,
        cm,
        pf,
        summary.total_value,
        app.account_map,
    ) catch {
        app.setStatus("Error computing analysis");
        return;
    };
}

// ── Rendering ─────────────────────────────────────────────────

pub fn buildStyledLines(app: *App, arena: std.mem.Allocator) ![]const StyledLine {
    return renderAnalysisLines(arena, app.theme, app.analysis_result);
}

/// Render analysis tab content. Pure function — no App dependency.
pub fn renderAnalysisLines(
    arena: std.mem.Allocator,
    th: theme_mod.Theme,
    analysis_result: ?zfin.analysis.AnalysisResult,
) ![]const StyledLine {
    var lines: std.ArrayList(StyledLine) = .empty;

    try lines.append(arena, .{ .text = "", .style = th.contentStyle() });
    try lines.append(arena, .{ .text = "  Portfolio Analysis", .style = th.headerStyle() });
    try lines.append(arena, .{ .text = "", .style = th.contentStyle() });

    const result = analysis_result orelse {
        try lines.append(arena, .{ .text = "  No analysis data. Ensure metadata.srf exists alongside portfolio.", .style = th.mutedStyle() });
        try lines.append(arena, .{ .text = "  Run: zfin enrich <portfolio.srf> > metadata.srf", .style = th.mutedStyle() });
        return lines.toOwnedSlice(arena);
    };

    const bar_width: usize = 30;
    const label_width: usize = 24;

    const sections = [_]struct { items: []const zfin.analysis.BreakdownItem, title: []const u8 }{
        .{ .items = result.asset_class, .title = "  Asset Class" },
        .{ .items = result.sector, .title = "  Sector (Equities)" },
        .{ .items = result.geo, .title = "  Geographic" },
        .{ .items = result.account, .title = "  By Account" },
        .{ .items = result.tax_type, .title = "  By Tax Type" },
    };

    for (sections, 0..) |sec, si| {
        if (si > 0 and sec.items.len == 0) continue;
        if (si > 0) try lines.append(arena, .{ .text = "", .style = th.contentStyle() });
        try lines.append(arena, .{ .text = sec.title, .style = th.headerStyle() });
        try lines.append(arena, .{ .text = "", .style = th.contentStyle() });
        for (sec.items) |item| {
            const text = try fmtBreakdownLine(arena, item, bar_width, label_width);
            try lines.append(arena, .{ .text = text, .style = th.contentStyle(), .alt_text = null, .alt_style = th.barFillStyle(), .alt_start = 2 + label_width + 1, .alt_end = 2 + label_width + 1 + bar_width });
        }
    }

    if (result.unclassified.len > 0) {
        try lines.append(arena, .{ .text = "", .style = th.contentStyle() });
        try lines.append(arena, .{ .text = "  Unclassified (not in metadata.srf)", .style = th.warningStyle() });
        for (result.unclassified) |sym| {
            const text = try std.fmt.allocPrint(arena, "    {s}", .{sym});
            try lines.append(arena, .{ .text = text, .style = th.mutedStyle() });
        }
    }

    return lines.toOwnedSlice(arena);
}

pub fn fmtBreakdownLine(arena: std.mem.Allocator, item: zfin.analysis.BreakdownItem, bar_width: usize, label_width: usize) ![]const u8 {
    var val_buf: [24]u8 = undefined;
    const pct = item.weight * 100.0;
    const bar = try buildBlockBar(arena, item.weight, bar_width);
    // Build label padded to label_width
    const lbl = item.label;
    const lbl_len = @min(lbl.len, label_width);
    const padded_label = try arena.alloc(u8, label_width);
    @memcpy(padded_label[0..lbl_len], lbl[0..lbl_len]);
    if (lbl_len < label_width) @memset(padded_label[lbl_len..], ' ');
    return std.fmt.allocPrint(arena, "  {s} {s} {d:>5.1}%  {s}", .{
        padded_label, bar, pct, fmt.fmtMoneyAbs(&val_buf, item.value),
    });
}

/// Build a bar using Unicode block elements for sub-character precision.
/// Wraps fmt.buildBlockBar into arena-allocated memory.
pub fn buildBlockBar(arena: std.mem.Allocator, weight: f64, total_chars: usize) ![]const u8 {
    var buf: [256]u8 = undefined;
    const result = fmt.buildBlockBar(&buf, weight, total_chars);
    return arena.dupe(u8, result);
}

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

const testing = std.testing;

test "buildBlockBar empty" {
    const bar = try buildBlockBar(testing.allocator, 0, 10);
    defer testing.allocator.free(bar);
    // All spaces
    try testing.expectEqual(@as(usize, 10), bar.len);
    try testing.expectEqualStrings("          ", bar);
}

test "buildBlockBar full" {
    const bar = try buildBlockBar(testing.allocator, 1.0, 5);
    defer testing.allocator.free(bar);
    // 5 full blocks, each 3 bytes UTF-8 (█ = E2 96 88)
    try testing.expectEqual(@as(usize, 15), bar.len);
    // Verify first block is █
    try testing.expectEqualStrings("\xe2\x96\x88", bar[0..3]);
}

test "buildBlockBar partial" {
    const bar = try buildBlockBar(testing.allocator, 0.5, 10);
    defer testing.allocator.free(bar);
    // 50% of 10 chars = 5 full blocks (no partial)
    // 5 full blocks (15 bytes) + 5 spaces = 20 bytes
    try testing.expectEqual(@as(usize, 20), bar.len);
}

test "fmtBreakdownLine formats correctly" {
    var arena_state = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena_state.deinit();
    const arena = arena_state.allocator();

    const item = zfin.analysis.BreakdownItem{
        .label = "US Stock",
        .weight = 0.65,
        .value = 130000,
    };
    const line = try fmtBreakdownLine(arena, item, 10, 12);
    // Should contain the label, percentage, and dollar amount
    try testing.expect(std.mem.indexOf(u8, line, "US Stock") != null);
    try testing.expect(std.mem.indexOf(u8, line, "65.0%") != null);
    try testing.expect(std.mem.indexOf(u8, line, "$130,000") != null);
}

test "renderAnalysisLines with data" {
    var arena_state = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena_state.deinit();
    const arena = arena_state.allocator();
    const th = theme_mod.default_theme;

    var asset_class = [_]zfin.analysis.BreakdownItem{
        .{ .label = "US Stock", .weight = 0.60, .value = 120000 },
        .{ .label = "Int'l Stock", .weight = 0.40, .value = 80000 },
    };
    const result = zfin.analysis.AnalysisResult{
        .asset_class = &asset_class,
        .sector = &.{},
        .geo = &.{},
        .account = &.{},
        .tax_type = &.{},
        .unclassified = &.{},
        .total_value = 200000,
    };
    const lines = try renderAnalysisLines(arena, th, result);
    // Should have header section + asset class items
    try testing.expect(lines.len >= 5);
    // Find "Portfolio Analysis" header
    var found_header = false;
    for (lines) |l| {
        if (std.mem.indexOf(u8, l.text, "Portfolio Analysis") != null) found_header = true;
    }
    try testing.expect(found_header);
    // Find asset class data
    var found_us = false;
    for (lines) |l| {
        if (std.mem.indexOf(u8, l.text, "US Stock") != null) found_us = true;
    }
    try testing.expect(found_us);
}

test "renderAnalysisLines no data" {
    var arena_state = std.heap.ArenaAllocator.init(testing.allocator);
    defer arena_state.deinit();
    const arena = arena_state.allocator();
    const th = theme_mod.default_theme;

    const lines = try renderAnalysisLines(arena, th, null);
    try testing.expectEqual(@as(usize, 5), lines.len);
    try testing.expect(std.mem.indexOf(u8, lines[3].text, "No analysis data") != null);
}