local World = require("game.world")
local Camera = require("game.camera")
local Player = require("game.player")
local Enemies = require("game.enemies")
local Obstacles = require("game.obstacles")
local Projectiles = require("game.projectiles")
local Horizon = require("game.horizon")
local Radar = require("game.radar")
local HUD = require("game.hud")
local HighScores = require("game.highscores")
local Effects = require("game.effects")
local Debris = require("game.debris")
local Input = require("game.input")
local Palette = require("rendering.palette")
local Fonts = require("rendering.fonts")
local Projection = require("rendering.projection")
local Models = require("data.models")
local Sounds = require("audio.sounds")

local RESPAWN_DELAY = 2.5
local engineTimer = 0

local function tryFire(pl)
    -- Authentic rule: "one shot on the playfield at a time." The reticle flashes
    -- while your shell is in flight and you can fire again the moment it dies.
    if pl.alive and not Projectiles.hasPlayerShot() then
        -- Spawn shot at barrel tip: forward = (sin, cos), 20 units ahead, slight barrel height
        Projectiles.fire(
            pl.x + math.sin(pl.angle) * 20,
            pl.z + math.cos(pl.angle) * 20,
            pl.angle, "player"
        )
        Sounds.play("fire")
    end
end

local function startGame()
    World.state = "playing"
    World.score = 0
    World.lives = 3
    World.nextExtraLife = 15000
    World.enemiesDestroyed = 0
    World.spawnTimer = 0
    World.gameOverTimer = 0

    Player.init()
    Enemies.init()
    Obstacles.init()
    Projectiles.clear()
    Effects.clear()
    Debris.clear()
    Radar.init()
    Camera.initViewport()

    Sounds.play("enemy_appear")
end

local FIRE_RETICLE_ARC = math.pi / 64  -- angular half-width for "enemy in sights" cue

local function enemyInSights(pl, enemy)
    if not (enemy and enemy.alive) then return false end
    local dx, dz = World.wrappedDist(pl.x, pl.z, enemy.x, enemy.z)
    local cosA = math.cos(pl.angle)
    local sinA = math.sin(pl.angle)
    local rx = dx * cosA - dz * sinA
    local rz = dx * sinA + dz * cosA
    if rz <= 0 then return false end
    return math.abs(math.atan2(rx, rz)) < FIRE_RETICLE_ARC
end

local function drawReticle(pl, enemy)
    local p = Palette.get()
    local sw, sh = World.screenW, World.screenH
    local cx, cy = sw / 2, sh / 2

    local size = sh * (100 / 900)
    local spacing = size / 1.8
    local inSights = enemyInSights(pl, enemy)

    -- Reticle flashes at 0.15s intervals whenever the player's shell is in flight
    -- (authentic arcade cue that you can't fire again yet).
    if Projectiles.hasPlayerShot() then
        local phase = math.floor(love.timer.getTime() / 0.15)
        if phase % 2 == 0 then return end
    end

    local curlLen = inSights and (size / 5) or (size / 10)
    local halfBar = size / 2

    love.graphics.setColor(p.tank)
    love.graphics.setLineWidth(math.max(1.4, sw / 1024 * 1.6))

    -- Top bracket: horizontal bar + vertical tick upward from centre
    love.graphics.line(cx - halfBar, cy - spacing, cx + halfBar, cy - spacing)
    love.graphics.line(cx, cy - spacing, cx, cy - spacing - size)

    -- Bottom bracket: mirror
    love.graphics.line(cx - halfBar, cy + spacing, cx + halfBar, cy + spacing)
    love.graphics.line(cx, cy + spacing, cx, cy + spacing + size)

    -- Bracket-end "curls": hang inward from each end of the two horizontal bars.
    -- Vertical when idle (short ticks), diagonal slanting inward when enemy is centred.
    local function curl(x, y, dirX, dirY, diagonal)
        if diagonal then
            love.graphics.line(x, y, x + dirX * curlLen, y + dirY * curlLen)
        else
            love.graphics.line(x, y, x, y + dirY * curlLen)
        end
    end

    -- Top bar ends: curls hang downward toward centre
    curl(cx - halfBar, cy - spacing, 1, 1, inSights)
    curl(cx + halfBar, cy - spacing, -1, 1, inSights)
    -- Bottom bar ends: curls reach upward toward centre
    curl(cx - halfBar, cy + spacing, 1, -1, inSights)
    curl(cx + halfBar, cy + spacing, -1, -1, inSights)
end

local function drawGameWorld()
    local pl = Player.get()
    local p = Palette.get()
    local sw, sh = World.screenW, World.screenH

    -- Background
    love.graphics.setColor(p.bg)
    love.graphics.rectangle("fill", 0, World.radarH, sw, World.viewH)

    -- Set scissor to 3D viewport
    love.graphics.setScissor(0, World.radarH, sw, World.viewH)

    Camera.update(pl)

    -- Mountains, horizon line, moon, smoke
    Horizon.draw(pl.angle)

    -- Obstacles
    love.graphics.setLineWidth(1.5)
    Obstacles.draw()

    -- Enemies
    Enemies.draw(pl.x, pl.z)

    -- Projectiles
    Projectiles.draw(pl.x, pl.z)

    -- Debris from tank destruction (3D tumbling wireframes)
    Debris.draw()

    love.graphics.setScissor()

    -- Reticle (two stacked brackets, curls flip + blink when enemy is in sights)
    if pl.alive then
        drawReticle(pl, Enemies.get())
    end

    -- Radar + HUD
    Radar.draw(pl, Enemies.get(), Obstacles.getAll())
    HUD.draw(pl, Enemies.get())
    Effects.draw()
end

local function drawTitleScreen()
    local p = Palette.get()
    local sw, sh = World.screenW, World.screenH
    local t = love.timer.getTime()

    -- Background
    love.graphics.setColor(p.bg)
    love.graphics.rectangle("fill", 0, 0, sw, sh)

    -- Rotating tank model in centre
    love.graphics.setScissor(0, sh * 0.15, sw, sh * 0.4)
    Projection.init(0, sh * 0.15, sw, sh * 0.4)
    Projection.setCamera(0, 0, 0)
    love.graphics.setColor(p.tank)
    love.graphics.setLineWidth(2)
    Projection.drawModel(Models.tank, 0, 0, 120, t * 0.5)
    love.graphics.setScissor()

    -- Restore viewport for gameplay
    Camera.initViewport()

    -- Title
    local titleY = sh * 0.05
    love.graphics.setFont(Fonts.large)
    love.graphics.setColor(p.bright)
    love.graphics.printf("OMA-TANK", 0, titleY, sw, "center")

    -- Controls / mode
    love.graphics.setFont(Fonts.small)
    love.graphics.setColor(p.fg[1], p.fg[2], p.fg[3], 0.5)
    local controlHint
    if Input.getMode() == "classic" then
        controlHint = "W/S: LEFT TRACK    I/K: RIGHT TRACK    SPACE: FIRE"
    else
        controlHint = "ARROWS / WASD: DRIVE    SPACE: FIRE"
    end
    love.graphics.printf(controlHint, 0, sh * 0.56, sw, "center")

    love.graphics.setColor(p.fg[1], p.fg[2], p.fg[3], 0.35)
    love.graphics.printf("MODE: " .. Input.label() .. "    [TAB] TO SWITCH", 0, sh * 0.60, sw, "center")

    -- Press Enter
    local pulse = 0.3 + math.sin(t * 3) * 0.3
    love.graphics.setFont(Fonts.medium)
    love.graphics.setColor(p.bright[1], p.bright[2], p.bright[3], pulse + 0.2)
    love.graphics.printf("PRESS ENTER TO START", 0, sh * 0.66, sw, "center")

    -- High scores
    local allScores = HighScores.getScores()
    if #allScores > 0 then
        HighScores.drawTable(sw, sh, p, Fonts)
    end
end

function love.load()
    math.randomseed(os.time())
    love.mouse.setVisible(false)
    love.graphics.setBackgroundColor(0, 0, 0)
    love.graphics.setLineStyle("smooth")
    Palette.loadFromSystem()
    World.resize(love.graphics.getDimensions())
    Fonts.init(World.scale)
    HighScores.init()
    Sounds.init()
    Horizon.init()
    Obstacles.init()
    Camera.initViewport()
    Input.load()
    Input.attachJoystick()
    World.highScore = HighScores.getHighest()
    World.state = "title"
end

function love.resize(w, h)
    World.resize(w, h)
    Fonts.init(World.scale)
    Camera.initViewport()
end

function love.update(dt)
    World.ensureScale()

    if World.state == "title" then
        return
    end

    if World.state == "playing" then
        local pl = Player.get()
        local leftT, rightT = Input.tracks()
        Player.update(dt, Obstacles.getAll(), leftT, rightT)

        -- Engine sound
        if pl.alive and Player.isMoving() then
            engineTimer = engineTimer + dt
            if engineTimer > 0.25 then
                engineTimer = 0
                Sounds.play("engine")
            end
        end

        -- (Anti-camping now handled in Enemies.update via each tank's lifetime
        --  vs. World.evadeDeadline — no per-frame timer needed here.)

        -- Motion-blocked sound cue (one-shot per sustained block)
        if pl.blockedJustTriggered then
            pl.blockedJustTriggered = false
            Sounds.play("motion_blocked")
        end

        Enemies.update(dt, pl.x, pl.z, pl.angle)
        Projectiles.update(dt, pl, Enemies.get(), Obstacles, Enemies.getUFO())
        Horizon.update(dt)
        Effects.update(dt)
        Debris.update(dt)

        -- Check if enemy was hit
        local enemy = Enemies.get()
        if enemy and not enemy.alive then
            local pts, ex, ez = Enemies.destroy()
            World.addScore(pts)
            Sounds.play("hit_enemy")
            Debris.explode(ex, 0, ez)
        end

        -- UFO hit processing (Projectiles.update flags .hit; finalise here)
        local ufo = Enemies.getUFO()
        if ufo and ufo.hit then
            local pts, ux, uz = Enemies.destroyUFO()
            World.addScore(pts)
            Sounds.play("hit_enemy")
            Debris.explode(ux, 40, uz)
        end

        -- Check if player was hit
        if pl.wasHit then
            pl.wasHit = false
            if pl.alive then
                Player.die()
                Sounds.play("hit_player")
                Sounds.play("screen_crack")
                Effects.triggerCrack()
                Debris.explode(pl.x, 0, pl.z)
                World.lives = World.lives - 1
            end
        end

        -- Respawn or game over
        if not pl.alive then
            if pl.deathTimer >= RESPAWN_DELAY then
                if World.lives > 0 then
                    -- On respawn the scene is reset: fresh obstacle placement,
                    -- enemy cleared, projectiles wiped, debris dropped.
                    Obstacles.init()
                    Enemies.clear()
                    Projectiles.clear()
                    Debris.clear()
                    Effects.clear()
                    Player.respawn()
                    Sounds.play("enemy_appear")
                else
                    World.state = "game_over"
                    World.gameOverTimer = 0
                    Sounds.play("hit_player")
                end
            end
        end

    elseif World.state == "game_over" then
        World.gameOverTimer = World.gameOverTimer + dt

    elseif World.state == "high_score_entry" then
        HighScores.updateEntry(dt)
    end
end

function love.draw()
    love.graphics.clear(0, 0, 0)
    local p = Palette.get()
    local sw, sh = World.screenW, World.screenH

    if World.state == "title" then
        drawTitleScreen()
        return
    end

    if World.state == "high_score_entry" then
        love.graphics.setColor(p.bg)
        love.graphics.rectangle("fill", 0, 0, sw, sh)
        HighScores.drawEntry(sw, sh, p, Fonts)
        return
    end

    drawGameWorld()

    if World.state == "game_over" then
        local t = love.timer.getTime()
        local midY = sh * 0.4

        -- Dim overlay
        love.graphics.setColor(0, 0, 0, 0.6)
        love.graphics.rectangle("fill", 0, World.radarH, sw, World.viewH)

        if World.gameOverTimer > 0.5 then
            love.graphics.setFont(Fonts.large)
            local textPulse = 0.7 + math.sin(t * 3) * 0.3
            love.graphics.setColor(p.bright[1], p.bright[2], p.bright[3], textPulse)
            love.graphics.printf("GAME OVER", 0, midY, sw, "center")
        end

        if World.gameOverTimer > 1.5 then
            love.graphics.setFont(Fonts.medium)
            love.graphics.setColor(p.fg[1], p.fg[2], p.fg[3], 0.7)
            love.graphics.printf("SCORE: " .. string.format("%09d", World.score), 0, midY + Fonts.large:getHeight() + 8, sw, "center")
        end

        if World.gameOverTimer > 2.5 then
            local pulse = 0.3 + math.sin(t * 3) * 0.3
            love.graphics.setFont(Fonts.small)
            love.graphics.setColor(p.bright[1], p.bright[2], p.bright[3], pulse + 0.2)
            love.graphics.printf("PRESS ENTER", 0, midY + Fonts.large:getHeight() + Fonts.medium:getHeight() + 24, sw, "center")
        end
    end
end

function love.keypressed(key)
    if World.state == "title" then
        if key == "return" then startGame() end
        if key == "tab" then Input.toggleMode() end
        if key == "escape" then love.event.quit() end
        return
    end

    if World.state == "high_score_entry" then
        local result = HighScores.keypressedEntry(key)
        if result == "done" then
            World.highScore = HighScores.getHighest()
            World.state = "title"
        end
        return
    end

    if World.state == "playing" then
        if key == "space" then tryFire(Player.get()) end
    end

    if World.state == "game_over" then
        if key == "return" and World.gameOverTimer > 2.0 then
            if HighScores.isHighScore(World.score) then
                World.state = "high_score_entry"
                HighScores.startEntry(World.score)
            else
                World.state = "title"
            end
            return
        end
        if key == "escape" then
            World.state = "title"
            return
        end
    end

    if key == "escape" then
        love.event.quit()
    end
end

function love.gamepadpressed(joystick, button)
    if World.state == "title" then
        if button == "start" or button == "a" then startGame() end
        if button == "back" or button == "y" then Input.toggleMode() end
        return
    end
    if World.state == "playing" then
        if button == "a" or button == "rightshoulder" then tryFire(Player.get()) end
        return
    end
    if World.state == "game_over" and World.gameOverTimer > 2.0 then
        if button == "a" or button == "start" then
            if HighScores.isHighScore(World.score) then
                World.state = "high_score_entry"
                HighScores.startEntry(World.score)
            else
                World.state = "title"
            end
        end
    end
end

function love.joystickadded(js)
    Input.joystickAdded(js)
end

function love.joystickremoved(js)
    Input.joystickRemoved(js)
end

function love.gamepadaxis(joystick, axis, value)
    -- Fire on right trigger press
    if axis == "triggerright" and value > 0.8 and World.state == "playing" then
        tryFire(Player.get())
    end
end