using System.Text.Json;
using System.Text.RegularExpressions;
using Age.Engine.Diagnostics;
using Age.Engine.Hosting;
using Age.Engine.Model;
using Age.Engine.Sys4;
using Age.Engine.Vm;

var table = OpcodeTableJson.Load(Paths.OpcodesJson);
// call-script execution: resolves ids -> scripts. Product paths pass this so subroutines run;
// `trace` stays provider-less on purpose (the base-ISA offset oracle).
var provider = Sys4ScriptProvider.Load(table);
Script ScriptByName(string name) => provider.RequireByName(name);

// Diagnostics flags (see the TraceSetup class below): --trace (text flow), --trace-steps (every op),
// --trace-ops <csv> (only these mnemonics/hex, tagged with their script), --trace-histogram (op +
// call-site execution counts, dumped after the run), --trace-file <path> (write to a file, else console).

if (args.Length == 0) { Console.WriteLine("usage: run <file> | trace <out.json>"); return 1; }

if (args[0] == "run")
{
    var script = Sys4Loader.Load(args[1], table);
    var runHost = new CaptureHost();
    using var trace = TraceSetup.Build(args, table);
    // Faithful by default: halt at wait-for-input (no player => stop, don't plow past prompts). --plow opts
    // into the old walk-every-page behavior (dialogue coverage). See VmOptions.HaltAtWaitForInput.
    var vm = new VirtualMachine(script, table, runHost, new VmOptions(HaltAtWaitForInput: !args.Contains("--plow")),
                                provider, trace.Sink);
    vm.Run();
    trace.Report();
    Console.WriteLine($"{Path.GetFileName(args[1])}: {vm.Steps} steps, {vm.Emitted.Count} show-text, {vm.CallScriptDispatches} call-scripts (halt: {vm.HaltReason})");
    foreach (var (off, text, scr) in vm.Emitted.Take(30)) Console.WriteLine($"  [{scr} 0x{off:x}] {text}");
    var sources = vm.Emitted.Select(e => e.Script).Distinct().ToList();
    Console.WriteLine($"source scripts ({sources.Count}): {string.Join(", ", sources)}");
    return 0;
}

if (args[0] == "audio")
{
    // audio <SCENE.BIN> — run the scene and dump executed play-bgm/play-voice ops in order,
    // each resolved via ResourceMap (same rule as the Godot host). Diagnostic only.
    var sceneName = args[1];
    var sceneKey = Path.GetFileNameWithoutExtension(sceneName).ToUpperInvariant();
    var res = ResourceMap.Load();
    var host = new AudioTraceHost(res, sceneKey);
    var vm = new VirtualMachine(ScriptByName(sceneName), table, host);
    // optional: seed globals, e.g. `audio SC0000.BIN 0xa57=1` to set Lily's form-A flag
    foreach (var s in args.Skip(2))
    {
        var kv = s.Split('=');
        int k = kv[0].StartsWith("0x") ? Convert.ToInt32(kv[0], 16) : int.Parse(kv[0]);
        long v = kv[1].StartsWith("0x") ? Convert.ToInt64(kv[1], 16) : long.Parse(kv[1]);
        vm.Globals[k] = v;
    }
    vm.Run();
    Console.WriteLine($"{sceneName}: {host.Events.Count} audio ops (halt: {vm.HaltReason})");
    foreach (var (kind, id, resolved) in host.Events)
        Console.WriteLine($"  {kind,-10} 0x{id:x2} -> {resolved}");
    return 0;
}

if (args[0] == "gfx")
{
    // gfx [--boot] <SCENE.BIN> [0xADDR=VAL ...] — run the scene and dump executed texture ops with resolved
    // file + computed geometry. --boot first runs SYSTEM4's state-setup prefix (INITCONFIG/INIT2/INIT,
    // skipping the UI scripts LOGO/OP/TITLE) through a GameSession, so scene-assumed boot state — chiefly
    // INIT2's gfx handle array 0x62455.. — is present. Diagnostic only.
    bool boot = args.Contains("--boot");
    var sceneName = args.First(a => a.EndsWith(".BIN", StringComparison.OrdinalIgnoreCase));
    var sceneKey = Path.GetFileNameWithoutExtension(sceneName).ToUpperInvariant();
    var res = ResourceMap.Load();
    var host = new GfxTraceHost(res, sceneKey);
    var session = new GameSession();
    foreach (var s in args.Where(a => a.Contains('=')))
    {
        var kv = s.Split('=');
        int k = kv[0].StartsWith("0x") ? Convert.ToInt32(kv[0], 16) : int.Parse(kv[0]);
        long v = kv[1].StartsWith("0x") ? Convert.ToInt64(kv[1], 16) : long.Parse(kv[1]);
        session.Seed(k, v);
    }
    if (boot)
        foreach (var b in new[] { "INITCONFIG.BIN", "INIT2.BIN", "INIT.BIN" })
        {
            var bs = session.RunScene(ScriptByName(b), table, new CaptureHost(), null, provider);
            Console.WriteLine($"[boot] {b}: {bs.Steps} steps (halt: {bs.Halt})");
        }
    var target = ScriptByName(sceneName);
    // With --boot, run the target like the real engine (call-scripts on) so subroutine-driven setup runs.
    var vm = boot ? new VirtualMachine(target, table, host, new VmOptions(MaxSteps: 20_000_000), provider)
                  : new VirtualMachine(target, table, host);
    foreach (var kv in session.Globals) vm.Globals[kv.Key] = kv.Value;
    foreach (var kv in session.GlobalStrings) vm.GlobalStrings[kv.Key] = kv.Value;
    vm.Run();
    Console.WriteLine($"{sceneName}: {host.Events.Count} texture ops (halt: {vm.HaltReason})");
    foreach (var line in host.Events) Console.WriteLine("  " + line);
    var gfxObjs = vm.Gfx.Objects.OrderBy(o => o.Slot).ToList();
    Console.WriteLine($"  gfx objects: {gfxObjs.Count} -> " +
        string.Join(", ", gfxObjs.Select(o => $"0x{o.Handle:x}=slot{o.Slot}")));
    var vis = vm.Gfx.SnapshotVisibleObjects();
    Console.WriteLine($"  visible objects ({vis.Count}, ascending-handle = z-order):");
    foreach (var v in vis)
        Console.WriteLine($"    h=0x{v.Handle:x} surf=0x{v.SurfaceResId:x} ({res.Resolve(sceneKey, v.SurfaceResId)?.Name ?? "?"}) src=({v.SrcX},{v.SrcY} {v.W}x{v.H}) dst=({v.DstX},{v.DstY})");
    return 0;
}

if (args[0] == "play")
{
    // play [--boot] <SCENE.BIN...> [0xADDR=VAL ...] — run a sequence of scenes carrying persistent global
    // state across them (optional up-front seeds). --boot first runs the data-table *INIT scripts so scenes
    // see the real skill/item/unit/etc. state. The state substrate for cross-scene flow; headless.
    // The *INIT boot set — all run clean (halt: exit) and populate the game's data tables into globals.
    string[] bootScripts = { "SKINIT.BIN", "ITINIT.BIN", "EBINIT.BIN", "CGINIT.BIN", "MPINIT.BIN",
                             "AFINIT.BIN", "CCINIT.BIN", "STINIT.BIN", "STINIT2.BIN" };
    bool boot = args.Contains("--boot");
    var userScenes = args.Skip(1).Where(a => a.ToUpperInvariant().EndsWith(".BIN")).ToList();
    if (userScenes.Count == 0) { Console.WriteLine("usage: play [--boot] <SCENE.BIN...> [0xADDR=VAL ...]"); return 1; }
    var scenes = (boot ? bootScripts.Concat(userScenes) : userScenes).ToList();
    // --state <file>: start from a saved snapshot (e.g. a pre-booted state) instead of booting fresh.
    string? StateArg(string flag) { int i = Array.IndexOf(args, flag); return i >= 0 && i + 1 < args.Length ? args[i + 1] : null; }
    var loadState = StateArg("--state");
    var saveState = StateArg("--save-state");
    var session = loadState != null ? GameSession.FromJson(File.ReadAllText(loadState)) : new GameSession();
    if (loadState != null) Console.WriteLine($"[state] loaded {session.Globals.Count} globals from {loadState}");
    foreach (var s in args.Skip(1).Where(a => a.Contains('=')))
    {
        var kv = s.Split('=');
        int k = kv[0].StartsWith("0x") ? Convert.ToInt32(kv[0], 16) : int.Parse(kv[0]);
        long v = kv[1].StartsWith("0x") ? Convert.ToInt64(kv[1], 16) : long.Parse(kv[1]);
        session.Seed(k, v);
    }
    long totalLines = 0;
    using var trace = TraceSetup.Build(args, table);   // one sink across the sequence (histogram aggregates)
    var playOpts = new VmOptions(HaltAtWaitForInput: !args.Contains("--plow"));   // faithful by default
    foreach (var name in scenes)
    {
        var script = ScriptByName(name);
        var r = session.RunScene(script, table, new CaptureHost(), playOpts, provider, trace.Sink);
        totalLines += r.Emitted.Count;
        Console.WriteLine($"  {name,-14} {r.Emitted.Count,4} lines, {r.Steps,7} steps (halt: {r.Halt})");
    }
    trace.Report();
    Console.WriteLine($"total: {totalLines} lines across {scenes.Count} scene(s); {session.Globals.Count} globals carried");
    if (saveState != null) { File.WriteAllText(saveState, session.ToJson()); Console.WriteLine($"[state] saved -> {saveState}"); }
    return 0;
}

if (args[0] == "sweep")
{
    // sweep [--boot] — run every SC/SP scene through GameSession (each from a fresh or booted-from-snapshot
    // baseline) and report halt distribution + line counts. Validates the VM + state substrate at scale and
    // surfaces how booted real data affects the corpus. Headless.
    var sceneRe = new Regex(@"^S[CP]\d{4}\.BIN$");
    var names = provider.ScriptNames.Where(n => sceneRe.IsMatch(n)).OrderBy(n => n, StringComparer.Ordinal).ToList();
    bool boot = args.Contains("--boot");
    // Sweep DEFAULTS to plow (walk every page) — it's the dialogue-coverage oracle. --halt-at-wait opts into
    // the faithful "stop at the first prompt" semantics (VmOptions.HaltAtWaitForInput).
    var sweepOpts = new VmOptions(HaltAtWaitForInput: args.Contains("--halt-at-wait"));
    string? baseline = null;
    if (boot)
    {
        var bootSession = new GameSession();
        foreach (var s in new[] { "SKINIT.BIN", "ITINIT.BIN", "EBINIT.BIN", "CGINIT.BIN", "MPINIT.BIN",
                                  "AFINIT.BIN", "CCINIT.BIN", "STINIT.BIN", "STINIT2.BIN" })
            bootSession.RunScene(ScriptByName(s), table, new CaptureHost(), null, provider);
        baseline = bootSession.ToJson();
        Console.WriteLine($"[boot] baseline = {bootSession.Globals.Count} globals; running {names.Count} scenes from it.");
    }
    // Optional seeds turn sweep into a story-state explorer: run each scene with AND without the seeds
    // (from the same baseline) and report which scenes' dialogue changes — i.e. what a story flag affects.
    var seeds = new List<(int, long)>();
    foreach (var s in args.Skip(1).Where(a => a.Contains('=')))
    {
        var kv = s.Split('=');
        int k = kv[0].StartsWith("0x") ? Convert.ToInt32(kv[0], 16) : int.Parse(kv[0]);
        long v = kv[1].StartsWith("0x") ? Convert.ToInt64(kv[1], 16) : long.Parse(kv[1]);
        seeds.Add((k, v));
    }
    GameSession Fresh() => baseline != null ? GameSession.FromJson(baseline) : new GameSession();
    int RunLines(string name, bool seeded)
    {
        var session = Fresh();
        if (seeded) foreach (var (k, v) in seeds) session.Seed(k, v);
        return session.RunScene(ScriptByName(name), table, new CaptureHost(), sweepOpts, provider).Emitted.Count;
    }

    if (seeds.Count > 0)
    {
        var changed = new List<string>();
        foreach (var name in names)
        {
            int baseLines = RunLines(name, false), seededLines = RunLines(name, true);
            if (baseLines != seededLines) changed.Add($"{name}: {baseLines} -> {seededLines} lines ({seededLines - baseLines:+#;-#;0})");
        }
        var seedStr = string.Join(" ", seeds.Select(s => $"0x{s.Item1:x}={s.Item2}"));
        Console.WriteLine($"seed [{seedStr}]{(boot ? " (booted)" : "")}: {changed.Count}/{names.Count} scenes change dialogue");
        foreach (var c in changed) Console.WriteLine("  " + c);
        return 0;
    }

    var haltDist = new SortedDictionary<string, int>(StringComparer.Ordinal);
    long totalLines = 0; var anomalies = new List<string>();
    using var trace = TraceSetup.Build(args, table);   // one sink across the corpus (histogram aggregates)
    foreach (var name in names)
    {
        var session = Fresh();
        var r = session.RunScene(ScriptByName(name), table, new CaptureHost(), sweepOpts, provider, trace.Sink);
        var halt = r.Halt ?? "null";
        haltDist[halt] = haltDist.GetValueOrDefault(halt) + 1;
        totalLines += r.Emitted.Count;
        if (halt != "exit") anomalies.Add($"{name}: {r.Emitted.Count} lines, halt={halt}");
    }
    trace.Report();
    Console.WriteLine($"swept {names.Count} scenes{(boot ? " (booted)" : "")}: {totalLines} total lines");
    Console.WriteLine("halt distribution: " + string.Join(", ", haltDist.Select(kv => $"{kv.Key}={kv.Value}")));
    if (anomalies.Count > 0) { Console.WriteLine($"non-exit halts ({anomalies.Count}):"); foreach (var a in anomalies) Console.WriteLine("  " + a); }
    return 0;
}

if (args[0] == "trace")
{
    // --trace-json <path>: single-scene per-op offset trace for the differential oracle (docs/engine-re.md).
    // Emits EVERY instruction offset the scene executes, in order (not just show-text lines), filtered to the
    // scene's own frame so call-script subroutines into other scripts are excluded — matching the Frida engine
    // tracer's per-codebase filter. --boot first runs SYSTEM4's state-setup prefix (INITCONFIG/INIT2/INIT) so
    // the scene sees real boot state, exactly like `gfx --boot`. Offsets are bytecode WORD indices, the same
    // unit the engine emits as (pc-codebase)/4. Observe-only (a step sink) — the sweep path below is untouched.
    int tji = Array.IndexOf(args, "--trace-json");
    if (tji >= 0)
    {
        if (tji + 1 >= args.Length) { Console.WriteLine("usage: trace <SCENE.BIN> [--boot] --trace-json <out.json>"); return 1; }
        var outPath = args[tji + 1];
        var sceneName = args.First(a => a.EndsWith(".BIN", StringComparison.OrdinalIgnoreCase));
        bool boot = args.Contains("--boot");
        var target = ScriptByName(sceneName);
        // --state <file>: start from a captured scene-entry snapshot (Frida global-write log →
        // capture_global_writes.py) — the real engine's full pre-scene state, superseding the partial
        // --boot. Otherwise fresh + optional --boot.
        int si = Array.IndexOf(args, "--state");
        var session = (si >= 0 && si + 1 < args.Length)
            ? GameSession.FromJson(File.ReadAllText(args[si + 1]))
            : new GameSession();
        // optional 0xADDR=VAL seeds — inject pre-scene state by hand (e.g. 0x6c1=1). Applied on top.
        foreach (var s in args.Where(a => a.Contains('=') && a != outPath))
        {
            var kv = s.Split('=');
            int k = kv[0].StartsWith("0x") ? Convert.ToInt32(kv[0], 16) : int.Parse(kv[0]);
            long v = kv[1].StartsWith("0x") ? Convert.ToInt64(kv[1], 16) : long.Parse(kv[1]);
            session.Seed(k, v);
        }
        if (boot && si < 0)   // --state already carries boot state; don't re-run the *INIT prefix
            foreach (var b in new[] { "INITCONFIG.BIN", "INIT2.BIN", "INIT.BIN" })
                session.RunScene(ScriptByName(b), table, new CaptureHost(), null, provider);
        var sink = new JsonOffsetTraceSink(target.Name);
        var vm = new VirtualMachine(target, table, new CaptureHost(),
                                    new VmOptions(HaltAtWaitForInput: true, MaxSteps: 20_000_000), provider, sink);
        foreach (var kv in session.Globals) vm.Globals[kv.Key] = kv.Value;
        foreach (var kv in session.GlobalStrings) vm.GlobalStrings[kv.Key] = kv.Value;
        vm.Run();
        var dir = Path.GetDirectoryName(outPath);
        if (!string.IsNullOrEmpty(dir)) Directory.CreateDirectory(dir);
        File.WriteAllText(outPath, JsonSerializer.Serialize(
            new { scene = Path.GetFileNameWithoutExtension(sceneName).ToUpperInvariant(), offsets = sink.Offsets },
            new JsonSerializerOptions { Encoder = System.Text.Encodings.Web.JavaScriptEncoder.UnsafeRelaxedJsonEscaping }));
        Console.WriteLine($"{sceneName}{(boot ? " (booted)" : "")}: {sink.Offsets.Count} offsets -> {outPath} (halt: {vm.HaltReason})");
        return 0;
    }

    var scene = new Regex(@"^S[CP]\d{4}\.BIN$");
    var trace = new SortedDictionary<string, object>(StringComparer.Ordinal);
    foreach (var name in provider.ScriptNames.Where(n => scene.IsMatch(n)).OrderBy(n => n, StringComparer.Ordinal))
    {
        var vm = new VirtualMachine(ScriptByName(name), table, new CaptureHost());
        vm.Run();
        trace[name] = new { offsets = vm.Emitted.Select(e => e.Offset).ToArray(), halt = vm.HaltReason, steps = vm.Steps };
    }
    File.WriteAllText(args[1], JsonSerializer.Serialize(trace,
        new JsonSerializerOptions { Encoder = System.Text.Encodings.Web.JavaScriptEncoder.UnsafeRelaxedJsonEscaping }));
    Console.WriteLine($"trace: {trace.Count} scenes -> {args[1]}");
    return 0;
}
Console.WriteLine("unknown command"); return 1;

// Assembles the diagnostic sink from CLI flags and owns the file writer + the post-run histogram dump.
// Inert (NullTraceSink) unless a --trace* flag is present, so normal runs are untouched (parity).
sealed class TraceSetup : IDisposable
{
    public ITraceSink Sink { get; private init; } = NullTraceSink.Instance;
    private HistogramTraceSink? _hist;
    private TextWriter? _file;              // owned file writer; null => console
    private OpcodeTable? _table;

    public static TraceSetup Build(string[] a, OpcodeTable tbl)
    {
        bool text = a.Contains("--trace");
        bool steps = a.Contains("--trace-steps");
        bool hist = a.Contains("--trace-histogram");
        string? opsCsv = ArgVal(a, "--trace-ops");
        if (!text && !hist && opsCsv == null) return new TraceSetup();   // inert

        int fi = Array.IndexOf(a, "--trace-file");
        TextWriter? file = null;
        if (fi >= 0 && fi + 1 < a.Length)
        {
            var path = a[fi + 1];
            var dir = Path.GetDirectoryName(path);
            if (!string.IsNullOrEmpty(dir)) Directory.CreateDirectory(dir);   // robust: create parent dir
            file = new StreamWriter(path) { AutoFlush = true };
        }
        TextWriter w = file ?? Console.Out;

        HashSet<int>? filter = null;
        if (opsCsv != null)
        {
            filter = new HashSet<int>();
            foreach (var tok in opsCsv.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries))
            {
                int? op = tok.StartsWith("0x") ? Convert.ToInt32(tok, 16) : tbl.ByLabel(tok);
                if (op is int o) filter.Add(o);
                else Console.Error.WriteLine($"--trace-ops: unknown op '{tok}' (ignored)");
            }
        }

        var sinks = new List<ITraceSink>();
        if (text || filter != null) sinks.Add(new TextTraceSink(w, tbl, steps, filter));
        HistogramTraceSink? h = null;
        if (hist) { h = new HistogramTraceSink(); sinks.Add(h); }

        return new TraceSetup
        {
            Sink = sinks.Count == 1 ? sinks[0] : new CompositeTraceSink(sinks.ToArray()),
            _hist = h, _file = file, _table = tbl,
        };
    }

    /// <summary>After the run, dump the histogram (if enabled). Text/filter output already streamed live.</summary>
    public void Report() => _hist?.WriteReport(_file ?? Console.Out, _table);

    public void Dispose() { _file?.Flush(); _file?.Dispose(); }

    private static string? ArgVal(string[] a, string key)
    { int i = Array.IndexOf(a, key); return i >= 0 && i + 1 < a.Length ? a[i + 1] : null; }
}

sealed class AudioTraceHost : IHost
{
    private readonly ResourceMap _res;
    private readonly string _scene;
    public List<(string Kind, long Id, string Resolved)> Events { get; } = new();
    public AudioTraceHost(ResourceMap res, string scene) { _res = res; _scene = scene; }
    public void PlayBgm(long id)                        // BGM: direct name, not the manifest
    {
        var entry = _res.ResolveBgm(id);
        Events.Add(("play-bgm", id, entry != null ? $"{entry.Archive} {entry.Name}" : $"BGM{id:D3}.OGG <missing>"));
    }
    public void PlayVoice(long id)                      // voice: per-scene manifest
    {
        var e = _res.Resolve(_scene, id);
        Events.Add(("play-voice", id, e == null ? "<unresolved>" : $"{e.Archive} {e.Name}"));
    }
    public void ShowText(int offset, string text) { }
    public void WaitForInput() { }
    public void Sleep(long duration) { }
    public void FrameYield() { }
    public void CreateTexture(int slot, int width, int height) { }
    public void SetTexture(long resourceId, int slot) { }
    public void DrawTexture(int slot, int srcX, int srcY, int width, int height, int dstX, int dstY) { }
    public (int Width, int Height) GetTextureSize(int slot) => (0, 0);
}

sealed class GfxTraceHost : IHost
{
    private readonly ResourceMap _res;
    private readonly string _scene;
    private readonly Dictionary<int, string?> _slotAsset = new(); // slot -> resolved AGF name (or null)
    // slot -> dims. Slot 0 is the primary/screen surface (800x600), normally created at engine boot which
    // the single-scene harness skips; seed it so the first CG's anchor math stays correct (not 0x0).
    private readonly Dictionary<int, (int W, int H)> _slotDims = new() { { 0, (800, 600) } };
    public List<string> Events { get; } = new();
    public GfxTraceHost(ResourceMap res, string scene) { _res = res; _scene = scene; }

    public (int Width, int Height) GetTextureSize(int slot)
    {
        var d = _slotDims.TryGetValue(slot, out var v) ? v : (0, 0);
        Events.Add($"get-tex-size slot={slot} -> {d.Item1}x{d.Item2}");
        return d;
    }

    public void SetTexture(long resId, int slot)
    {
        var e = _res.ResolveTexture(_scene, resId);
        RgbaImage? image = e != null ? _res.DecodeTexture(e) : null;
        _slotAsset[slot] = e?.Name;
        _slotDims[slot] = image != null ? (image.Width, image.Height) : (0, 0);
        Events.Add($"set-texture slot={slot} res=0x{resId:x} -> {(e?.Name ?? "<unresolved>")}"
                   + (image == null ? " [NO AGF]" : ""));
    }

    public void DrawTexture(int slot, int sx, int sy, int w, int h, int dx, int dy)
    {
        _slotAsset.TryGetValue(slot, out var asset);
        Events.Add($"draw-texture slot={slot} src=({sx},{sy} {w}x{h}) dst=({dx},{dy}) "
                   + $"file={(asset ?? "<none>")}");
    }

    public void CreateTexture(int slot, int width, int height)
    {
        _slotDims[slot] = (width, height);
        Events.Add($"create-texture slot={slot} {width}x{height}");
    }
    public void ShowText(int offset, string text) { }
    public void WaitForInput() { }
    public void Sleep(long duration) { }
    public void FrameYield() { }
    public void PlayBgm(long id) { }
    public void PlayVoice(long id) { }
}