const w4 = @import("./wasm4.zig");
const sh0rk = @import("./sh0rk.zig");
const sprites = @import("./sprites.zig");
const palette = @import("./palette.zig");
const tframe = @import("./tframe.zig");

const std = @import("std");
const fmt = std.fmt;

const Direction = sh0rk.Direction;
const Point = sh0rk.Point;
const Rect = sh0rk.Rect;

const map = @import("./maps/overworld.zig");

var frame_count: u32 = 0;
var mara_direction: Direction = Direction.Right;
var mara_frame: bool = false;
var mara_box: Rect = Rect{ .base = map.start_point, .width = 16, .height = 16 };
var mara_speed: i16 = 0;
var old_speed: i16 = 0;
var screen = Rect{ .base = Point{ .x = 0, .y = 0 }, .width = 160, .height = 160 };

const screen_width = 20;
const screen_height = 20;
const tile_size: i16 = 8;

var sound_timer: u8 = 0;

var textBuf: [160]u8 = undefined;
var done: bool = false;

var camera = Point{ .x = 0, .y = 0 };

var state: sh0rk.State = .Gameplay;

fn world_to_screen(p: Point) Point {
    p.sub(camera);
}

fn screen_to_world(p: Point) Point {
    p.add(camera);
}

export fn start() void {
    palette.mist();
}

fn bonk() void {
    if (sound_timer != 0) {
        return;
    }

    w4.tone(
        w4.Tone.Frequency{ .start = 220, .end = 40 },
        w4.Tone.Duration{
            .attack = 0,
            .decay = 0,
            .sustain = 6,
            .release = 6,
        },
        w4.Tone.Volume{
            .sustain = 100,
            .attack = 100,
        },
        w4.Tone.Flags{
            .channel = .triangle,
            .pulse_duty = .@"1/4",
        },
    );

    sound_timer = 12;
}

fn drawMap() !void {
    switch (map.tileset) {
        .Dungeon => {
            w4.m.colors.* = .{
                ._0 = .p2,
                ._1 = .p0,
                ._2 = .p1,
                ._3 = .p3,
            };
        },
        .Rpg => {
            w4.m.colors.* = .{
                ._0 = .p3,
                ._1 = .p2,
                ._2 = .p1,
                ._3 = .p0,
            };
        },
    }
    if (!done) {
        var buf = fmt.bufPrint(&textBuf, "camera: {},{}", .{ camera.x, camera.y }) catch unreachable;
        w4.trace(buf);
    }

    var startCol: i32 = @divTrunc(camera.x, tile_size);
    var endCol = startCol + screen_width;
    var startRow: i32 = @divTrunc(camera.y, tile_size);
    var endRow = startRow + screen_height;

    var offsetX = startCol * tile_size;
    var offsetY = startRow * tile_size;

    if (!done) {
        var buf = fmt.bufPrint(&textBuf, "{},{}: {},{}", .{ startCol, startRow, endCol, endRow }) catch unreachable;
        w4.trace(buf);
    }
    if (!done) {
        var buf = fmt.bufPrint(&textBuf, "offx: {}, offy: {}", .{ offsetX, offsetY }) catch unreachable;
        w4.trace(buf);
    }

    var col: i32 = startCol;
    while (col < endCol) {
        var row: i32 = startRow;
        defer col += 1;
        while (row < endRow) {
            defer row += 1;

            var tile = map.get_tile(@intCast(u32, col), @intCast(u32, row));

            var x = (row - startCol) * tile_size - offsetX;
            var y = (col - startRow) * tile_size - offsetY;

            if (x < 0) {
                x = x * -1;
            }
            if (y < 0) {
                y = y * -1;
            }

            if (!done) {
                var buf = fmt.bufPrint(&textBuf, "{},{}: {}: {},{}", .{ col, row, tile, x, y }) catch unreachable;
                w4.trace(buf);
            }

            draw_tile(tile, @intCast(u32, x), @intCast(u32, y));
        }
    }
}

fn draw_tile(tile: u32, x: u32, y: u32) void {
    if (tile == 0) {
        w4.rect(x, y, 8, 8);
        return;
    }

    var tileX = (tile - 1) % map.ts_width;
    var tileY = (tile - 1) / map.ts_width;

    switch (map.tileset) {
        .Rpg => w4.blitSub(
            &sprites.kenney_rpg,
            x,
            y,
            8,
            8,
            @intCast(u32, tileX) * 8,
            @intCast(u32, tileY) * 8,
            sprites.kenney_rpg_width,
            w4.BlitFlags{ .two_bits = true },
        ),
        .Dungeon => w4.blitSub(
            &sprites.dungeon,
            x,
            y,
            8,
            8,
            @intCast(u32, tileX) * 8,
            @intCast(u32, tileY) * 8,
            sprites.dungeon_width,
            w4.BlitFlags{ .two_bits = true },
        ),
    }
}

fn move_mara(gamepad: w4.GamePad) void {
    if (mara_speed > 0) {
        mara_speed -= 1;
    }
    if (gamepad.up) {
        mara_direction = Direction.Up;
        mara_speed = 1;
    } else if (gamepad.down) {
        mara_direction = Direction.Down;
        mara_speed = 1;
    } else if (gamepad.left) {
        mara_direction = Direction.Left;
        mara_speed = 1;
    } else if (gamepad.right) {
        mara_direction = Direction.Right;
        mara_speed = 1;
    }

    switch (mara_direction) {
        .Up => {
            mara_box.base.y -= mara_speed;
        },
        .Down => {
            mara_box.base.y += mara_speed;
        },
        .Left => {
            mara_box.base.x -= mara_speed;
        },
        .Right => {
            mara_box.base.x += mara_speed;
        },
    }
}

fn title() !void {
    w4.m.colors._0 = .p3;
    w4.m.colors._1 = .p0;
    w4.text("Mara 2:\nTamamo's Fury", 28, 8);
    w4.text("Press z or x", 32, 136);
    w4.text("From Within 2022", 16, 152);

    w4.m.colors._0 = .p0;
    w4.m.colors._1 = .p1;
    w4.m.colors._2 = .p2;
    w4.m.colors._3 = .p3;

    w4.blit(&sprites.tamamotitle, 48, 60, sprites.tamamotitle_width, sprites.tamamotitle_height, w4.BlitFlags{ .two_bits = true });

    const gamepad = w4.m.gamepads[0];
    if (gamepad.a or gamepad.b) {
        state = .StoryDump;
    }
}

const story = "After defeating\nthe evil mage,\nMalto was at\npeace.\n\nOne day Mara was\nwalking along the\nbeach when she saw\nthe killing stone\nwas split in two.\nTamamo-no-Mae was\nfree to wreak havoc\nacross the land.\n\nHelp us again Mara!\nSave Kanar from\nTamamo-no-Mae!\n\nPress x.";
var story_idx: usize = 0;
var story_counter: u8 = 4;

fn storydump() !void {
    w4.m.colors._0 = .p3;
    w4.m.colors._1 = .p0;

    w4.text(story[0..story_idx], 4, 4);

    const gamepad = w4.m.gamepads[0];
    if (gamepad.b) {
        state = .Gameplay;
        palette.mist();
    }

    if (story_idx < story.len) {
        story_counter -= 1;

        if (gamepad.a) {
            story_counter = 0;
        }

        if (story_counter == 0) {
            story_idx += 1;
            story_counter = 4;

            w4.tone(
                w4.Tone.Frequency{ .start = 280, .end = 310 },
                w4.Tone.Duration{
                    .attack = 0,
                    .decay = 0,
                    .sustain = 2,
                    .release = 0,
                },
                w4.Tone.Volume{
                    .sustain = 100,
                    .attack = 100,
                },
                w4.Tone.Flags{
                    .channel = .triangle,
                    .pulse_duty = .@"1/4",
                },
            );
        }
    } else {
        if (gamepad.a) {
            state = .Gameplay;
            palette.mist();
        }
    }
}

export fn update() void {
    defer frame_count += 1;

    switch (state) {
        .Title => title() catch unreachable,
        .StoryDump => storydump() catch unreachable,
        .Gameplay => gameplay() catch unreachable,
    }
}

fn gameplay() !void {
    defer done = true;
    if (sound_timer != 0) {
        sound_timer -= 1;
    }

    drawMap() catch unreachable;

    const gamepad = w4.m.gamepads[0];

    if (!tframe.enabled) {
        move_mara(gamepad);
    } else {
        tframe.update(gamepad);
    }

    for (map.coll) |box| {
        if (mara_box.collides(box)) {
            switch (mara_direction) {
                .Up => {
                    mara_box.base.y += mara_speed;
                },
                .Down => {
                    mara_box.base.y -= mara_speed;
                },
                .Left => {
                    mara_box.base.x += mara_speed;
                },
                .Right => {
                    mara_box.base.x -= mara_speed;
                },
            }
            mara_speed = 0;
            bonk();
        }
    }

    for (map.triggers) |trig| {
        if (mara_box.collides(trig.aura) and mara_direction == trig.direction and gamepad.b) {
            tframe.set_text(trig.dialogue);
        }
    }

    if (mara_box.base.x <= 0) {
        mara_box.base.x = 0;
        bonk();
    }

    if (mara_box.base.y <= 0) {
        mara_box.base.y = 0;
        bonk();
    }

    draw_mara();
}

fn draw_glaceon(p: Point) void {
    palette.mist();
    w4.m.colors.* = .{
        ._0 = .p0,
        ._1 = .p1,
        ._2 = .p3,
        ._3 = .transparent,
    };

    w4.blit(&sprites.glaceon, p.x, p.y, sprites.glaceon_width, sprites.glaceon_height, w4.BlitFlags{ .two_bits = true });
}

fn draw_mara() void {
    var flags: w4.BlitFlags = w4.BlitFlags{
        .two_bits = true,
    };

    w4.m.colors.* = .{
        ._0 = .transparent,
        ._1 = .p0,
        ._2 = .p1,
        ._3 = .p3,
    };

    if (mara_direction == Direction.Left) {
        flags.flip_x = true;
    }

    if (frame_count % 32 == 0 and mara_speed > 0) {
        mara_frame = !mara_frame;
    }

    var frame: u32 = switch (mara_direction) {
        .Left => 4,
        .Right => 4,
        .Up => 2,
        .Down => 0,
    };
    var step: u32 = if (mara_frame) 1 else 0;

    w4.blitSub(&sprites.Mara, @intCast(u32, mara_box.base.x), @intCast(u32, mara_box.base.y), 16, 16, 16 * (frame + step), 0, 96, flags);
}

pub fn panic(msg: []const u8, st: ?*std.builtin.StackTrace) noreturn {
    _ = st;
    w4.trace("!!! PANIC !!!");
    w4.trace(msg);
    while (true) {}
}