-- sporel-module-vagrant-skeleton v0.5.0
-- Sprite-mode test-chamber: 13-bone humanoid puppet + sprite-tilemap +
-- hardcoded furniture. Subterrain-style puppet control model:
-- multi-look-target (aim/soft), slerp body rotation, hip-static legs,
-- foot-body-orientation. Sprint (shift+wasd) + interaction (E near
-- backpack) added v0.4.4.

local input       = require("lib-core.input")
local camera      = require("lib-core.camera")
local r_lib       = require("lib-core.render")
local maps        = require("lib-core.maps")
local puppet      = require("lib-core.puppet")
local interaction = require("lib-core.interaction")

local M = {}

-- Walk + sprint speed tunings.
local WALK_SPEED_NORMAL = 120
local WALK_SPEED_SPRINT = 240        -- 2x
local ANIM_SPEED_NORMAL = 0.45
local ANIM_SPEED_SPRINT = 0.9        -- 2x

-- Furniture positions (matches M.draw hardcoded sprites).
local BACKPACK_X, BACKPACK_Y = 350, 400
local INTERACTION_RANGE = 40         -- pixels

local state = {
    player = nil,
    map = nil,
    world_tex = nil,         -- subterrain_world atlas diffuse handle
    furniture_uvs = nil,     -- name -> { x, y, w, h } from atlas JSON
    -- Subterrain-style controller state:
    walk_anim_current = nil,   -- "walk_fwd_lower" / "walk_back_lower" / etc. (nil = idle_lower)
    lower_control_rot_deg = 0,
    move_x = 0,
    move_y = 0,
    sprinting = false,         -- shift+wasd = 2x speed + 2x anim
}

-- CI hook gating (mirrors Phase 1 convention).
local CI_FRAME_PERF = (os.getenv("SPOREL_CI") == "1")
local CI_DRIVE      = (os.getenv("SPOREL_VAGRANT_PHASE1_DRIVE") == "1")
local ci_frame_count = 0
local ci_t_start     = nil
local ci_drive_frame = 0
local ci_last_state  = nil
local ci_sprite_traced = false
local ci_assets_traced = false

-- All 4 directional walk animation ids.
local WALK_ANIMS = {"walk_fwd_lower", "walk_back_lower", "walk_left_lower", "walk_right_lower"}

-- Signed angle between two 2D vectors (in degrees, range [-180, 180]).
-- Sporel uses Y-down screen-coords. Substrate's math assumes Y-up; the cross
-- component is flipped so "positive num = move-direction is CCW from body-fwd
-- in screen-coords" matches substrate's "positive num = walk_left sector".
local function signed_angle_2d(v1x, v1y, v2x, v2y)
    local cross = v1y * v2x - v1x * v2y   -- Y-down flip
    local dot   = v1x * v2x + v1y * v2y
    return math.deg(math.atan(cross, dot))
end

-- Given signed angle num_deg from body-forward to move-direction, pick the
-- appropriate walk animation and compute the lower_control offset rotation (degrees).
-- Substrate convention: body-forward = sprite top = -Y at rot=0.
local function pick_walk_anim(num_deg)
    if num_deg >= -45 and num_deg <= 45 then
        -- Movement roughly aligns with body-forward = backpedaling
        return "walk_back_lower", math.max(-30, math.min(30, num_deg))
    elseif num_deg > 45 and num_deg < 135 then
        -- Movement ~90° left of body-forward = strafe left
        return "walk_left_lower", math.max(60, math.min(120, num_deg)) - 90
    elseif num_deg > -135 and num_deg < -45 then
        -- Movement ~90° right of body-forward = strafe right
        return "walk_right_lower", math.max(-120, math.min(-60, num_deg)) + 90
    elseif num_deg > 0 then
        -- Movement roughly opposite body-forward, positive side = walk forward
        return "walk_fwd_lower", -(30 - (math.max(150, math.min(180, num_deg)) - 150))
    else
        -- Movement roughly opposite body-forward, negative side = walk forward
        return "walk_fwd_lower", 30 + (math.max(-180, math.min(-150, num_deg)) + 150)
    end
end

-- Lower-body controller: legs rotate to walk direction (NOT Substrate's
-- body-relative wedge). User preference: leg stride visually aligns with
-- movement axis. lower_control.rot = atan(move_x, -move_y) so leg sprites
-- (which oscillate scl_y along their local Y) cycle along the walk axis.
-- One generic walk_fwd_lower anim suffices since the rotation handles
-- the directional change (4-direction anims kept on disk for future
-- gait-style differentiation).
local function update_lower_anim(moving, move_x, move_y)
    if not moving then
        -- Idle: stop walk anims, resume idle_lower. Preserve last
        -- lower_control_rot_deg so legs keep their last orientation
        -- (no snap-back to north on stop).
        if state.walk_anim_current ~= nil then
            for _, a in ipairs(WALK_ANIMS) do
                puppet.stop(state.player, a)
            end
            state.walk_anim_current = nil
            puppet.play(state.player, "idle_lower", { loop = true })
            puppet.stop(state.player, "walk_upper")
            if not puppet.is_playing(state.player, "idle") then
                puppet.play(state.player, "idle", { loop = true })
            end
            if CI_FRAME_PERF and ci_last_state ~= "idle" then
                engine.print("vagrant: state=idle")
                ci_last_state = "idle"
            end
        end
        return
    end

    -- Walking: legs face walk direction (sprite-top convention: rot=0 = -Y).
    state.lower_control_rot_deg = math.deg(math.atan(move_x, -move_y))

    -- Single generic walk anim (4-direction-picker deferred until we have
    -- differentiated gait styles per direction).
    local anim_id = "walk_fwd_lower"
    if state.walk_anim_current ~= anim_id then
        for _, a in ipairs(WALK_ANIMS) do
            if a ~= anim_id then puppet.stop(state.player, a) end
        end
        puppet.stop(state.player, "idle_lower")
        puppet.stop(state.player, "idle")
        -- Play with current speed (normal or sprint).
        local anim_speed = state.sprinting and ANIM_SPEED_SPRINT or ANIM_SPEED_NORMAL
        puppet.play(state.player, anim_id, { loop = true, speed = anim_speed })
        if not puppet.is_playing(state.player, "walk_upper") then
            puppet.play(state.player, "walk_upper", { loop = true, speed = anim_speed })
        end
        state.walk_anim_current = anim_id
        if CI_FRAME_PERF and ci_last_state ~= "walk" then
            engine.print("vagrant: state=walk")
            ci_last_state = "walk"
        end
    end
end

function M.init(ctx)
    local aliases = engine.module.asset_aliases()

    -- Map + sprite-tilemap.
    state.map = maps.load("maps/vagrant_test.map.json")
    maps.set_current(state.map)
    maps.load_textures(aliases)

    -- Puppet rig + sprite textures.
    local rig = puppet.load_rig("rigs/humanoid.rig.json", aliases)
    state.player = puppet.spawn(rig, { x = 320, y = 240 })

    -- Load all animations.
    local walk_fwd   = puppet.load_animation("animations/walk_fwd_lower.anim.json", rig)
    local walk_back  = puppet.load_animation("animations/walk_back_lower.anim.json", rig)
    local walk_left  = puppet.load_animation("animations/walk_left_lower.anim.json", rig)
    local walk_right = puppet.load_animation("animations/walk_right_lower.anim.json", rig)
    local walk_upper = puppet.load_animation("animations/walk_upper.anim.json", rig)
    local idle       = puppet.load_animation("animations/idle.anim.json", rig)
    local idle_lower = puppet.load_animation("animations/idle_lower.anim.json", rig)

    for _, a in ipairs({walk_fwd, walk_back, walk_left, walk_right, walk_upper, idle, idle_lower}) do
        puppet.register_animation(state.player, a)
    end

    -- Start in idle state.
    puppet.play(state.player, "idle",       { loop = true })
    puppet.play(state.player, "idle_lower", { loop = true })

    -- Procedural leg+foot orientation:
    -- * Hips are body-relative (legs.parent=body, position cascade follows body).
    -- * leg.world.rot = walk_dir (independent of body). Set leg.local.rot =
    --   walk_dir - body.world.rot so cascade gives correct world rot.
    -- * foot.world.rot = body.world.rot (user pref: feet stay body-oriented
    --   even when legs swing to walk-direction = "tactical twist"). Cascade:
    --   foot.world.rot = leg.world.rot + foot.local.rot = body.rot.
    --   → foot.local.rot = body.rot - leg.world.rot = body.rot - walk_dir
    --   = -leg_local_deg.
    -- Per-channel guard v0.4.2 allows leg.rot + foot.rot writes alongside
    -- walk_fwd_lower (which only writes leg.scl).
    puppet.set_procedural(state.player, "leg_foot_orientation", function(handle, dt)
        local _, _, body_rot = puppet.bone_world_transform(handle, "body")
        local leg_local_deg  = state.lower_control_rot_deg - math.deg(body_rot)
        local foot_local_deg = -leg_local_deg
        puppet.write_bone(handle, "leg_l",  { rot = leg_local_deg  })
        puppet.write_bone(handle, "leg_r",  { rot = leg_local_deg  })
        puppet.write_bone(handle, "foot_l", { rot = foot_local_deg })
        puppet.write_bone(handle, "foot_r", { rot = foot_local_deg })
    end)

    -- Furniture atlas (subterrain_world): load JSON + diffuse texture once.
    local world_lib  = aliases.subterrain_world
    local world_base = world_lib .. "/assets/atlases/subterrain_world"
    local world_meta = engine.asset.load_json(world_base .. "/tiles.atlas.json")
    state.world_tex  = engine.asset.load_texture(world_base .. "/tiles.diffuse.atlas.png")
    state.furniture_uvs = {}
    for _, t in ipairs(world_meta.tiles) do
        state.furniture_uvs[t.name] = { x = t.uv[1], y = t.uv[2], w = t.uv[3], h = t.uv[4] }
    end

    -- Input bindings.
    input.bind("walk_left",  { "a" })
    input.bind("walk_right", { "d" })
    input.bind("walk_up",    { "w" })
    input.bind("walk_down",  { "s" })
    input.bind("sprint",     { "shift" })   -- held while walking → 2x speed
    input.bind("interact",   { "e" })       -- fires nearest proximity-trigger
    input.bind("quit_to_launcher", { "escape" })

    -- Proximity trigger on the backpack sprite (drawn at BACKPACK_X/Y in M.draw).
    -- Range 40px; press E while within that radius to fire the callback.
    interaction.register(BACKPACK_X, BACKPACK_Y, INTERACTION_RANGE, "interact", function(ctx)
        engine.print(string.format(
            "vagrant: interact with backpack (distance=%.1f)",
            ctx.distance))
    end)

    -- CI trace: assets loaded count (3 atlas textures: player + tiles + world).
    if CI_FRAME_PERF and not ci_assets_traced then
        engine.print("vagrant: assets_loaded=3")
        ci_assets_traced = true
    end

    if CI_FRAME_PERF then
        ci_t_start = engine.time.now()
    end
end

function M.update(ctx, dt)
    if input.was_action_pressed("quit_to_launcher") then
        engine.switch_module("lib-sporel.launcher")
        return
    end

    -- WASD input → normalized move vector.
    local dx, dy = 0, 0
    if input.is_action_down("walk_left")  then dx = dx - 1 end
    if input.is_action_down("walk_right") then dx = dx + 1 end
    if input.is_action_down("walk_up")    then dy = dy - 1 end
    if input.is_action_down("walk_down")  then dy = dy + 1 end
    local moving = (dx ~= 0 or dy ~= 0)

    -- Sprint = shift held + actually moving. Updated BEFORE move so the
    -- selected speed matches; also feeds update_lower_anim's anim-speed
    -- pick at walk-start transitions.
    local sprint_held = input.is_action_down("sprint")
    state.sprinting = moving and sprint_held
    local current_walk_speed = state.sprinting and WALK_SPEED_SPRINT or WALK_SPEED_NORMAL

    -- CI_DRIVE: synthetic scripted move (preserve existing P0-S25b semantics).
    if CI_DRIVE then
        ci_drive_frame = ci_drive_frame + 1
        if ci_drive_frame > 20 and ci_drive_frame <= 40 then
            dx = 1; dy = 0
            moving = true
            local pos = puppet.position(state.player)
            puppet.move_to(state.player,
                pos.x + dx * WALK_SPEED_NORMAL * dt, pos.y)
        else
            moving = false
        end
    end

    -- Move puppet.
    if moving and not CI_DRIVE then
        local len = math.sqrt(dx * dx + dy * dy)
        state.move_x = dx / len
        state.move_y = dy / len
        local pos = puppet.position(state.player)
        puppet.move_to(state.player,
            pos.x + state.move_x * current_walk_speed * dt,
            pos.y + state.move_y * current_walk_speed * dt)
    elseif not moving then
        state.move_x = 0
        state.move_y = 0
    end

    -- CI_DRIVE move_x/move_y for anim selection.
    if CI_DRIVE and moving then
        state.move_x = dx
        state.move_y = dy
    end

    update_lower_anim(moving, state.move_x, state.move_y)

    -- Sprint toggle mid-walk: adjust play-speed of running anims without
    -- restarting their cycle (puppet v0.4.4 set_play_speed). Silent no-op
    -- if anim not currently playing.
    local anim_speed = state.sprinting and ANIM_SPEED_SPRINT or ANIM_SPEED_NORMAL
    puppet.set_play_speed(state.player, "walk_fwd_lower", anim_speed)
    puppet.set_play_speed(state.player, "walk_upper",     anim_speed)

    -- Look-targets: head tracks raw mouse (aim), body tracks same for now (soft).
    local mx, my = engine.input.get_mouse_pos()
    local wx, wy = camera.screen_to_world(mx, my)
    puppet.set_look_target(state.player, "aim",  wx, wy)
    puppet.set_look_target(state.player, "soft", wx, wy)

    -- Interaction: dispatches the nearest matching proximity-trigger when
    -- 'interact' was pressed this frame. Uses player.position as actor.
    local pos = puppet.position(state.player)
    interaction.update(pos.x, pos.y)

    -- Camera follows puppet position each frame.
    camera.set_target(pos.x, pos.y)
    camera.update(dt)

    puppet.update(dt)

    if CI_FRAME_PERF and ci_t_start then
        ci_frame_count = ci_frame_count + 1
        if ci_frame_count == 60 then
            local elapsed_ms = (engine.time.now() - ci_t_start) * 1000.0
            local avg = elapsed_ms / 60.0
            print(string.format("vagrant: frame_avg_ms=%.2f", avg))
            engine.exit(0)
        end
    end
end

function M.draw(ctx)
    camera.begin()
        maps.draw_map_pre_entities()
        -- Hardcoded furniture placements (test-chamber spirit).
        -- Render via source-rect primitive using subterrain_world atlas UVs.
        local bed_uv      = state.furniture_uvs["bed_001"]
        local bench_uv    = state.furniture_uvs["bench_001"]
        local backpack_uv = state.furniture_uvs["backpack_001"]
        engine.render.draw_sprite_transform(state.world_tex, 200, 150, 0, 1, 1,
            bed_uv.w / 2, bed_uv.h / 2, 0xFFFFFFFF,
            bed_uv.x, bed_uv.y, bed_uv.w, bed_uv.h)
        engine.render.draw_sprite_transform(state.world_tex, 400, 300, 0, 1, 1,
            bench_uv.w / 2, bench_uv.h / 2, 0xFFFFFFFF,
            bench_uv.x, bench_uv.y, bench_uv.w, bench_uv.h)
        engine.render.draw_sprite_transform(state.world_tex, 350, 400, 0, 1, 1,
            backpack_uv.w / 2, backpack_uv.h / 2, 0xFFFFFFFF,
            backpack_uv.x, backpack_uv.y, backpack_uv.w, backpack_uv.h)
        -- Puppet (sprite-mode via texture_handles populated by load_rig+load_textures).
        puppet.render(state.player)
        maps.draw_map_post_entities()
    camera.finish()
    if CI_FRAME_PERF then
        engine.print("vagrant: render_frame_ok")
        if not ci_sprite_traced then
            engine.print("vagrant: sprite_mode=on")
            ci_sprite_traced = true
        end
    end
end

-- Engine lifecycle globals (engine looks up by name; module-table is bridged).
function init(ctx)         M.init(ctx)        end
function update(ctx, dt)   M.update(ctx, dt)  end
function render(ctx)       M.draw(ctx)        end

return M