-- =====================================================================
-- lib-core.player_control v0.2.0 — Input → Actor Movement + AABB-Collision
-- See: meta/docs/superpowers/specs/2026-05-09-p0-lib-player_control-design.md
--      meta/docs/superpowers/specs/2026-06-09-phase-A-...
--
-- v0.2.0 (Phase A.6) — BREAKING REFACTOR:
--   Position/size/speed leben jetzt auf einer Actor-Entity (lib-core.actor
--   + lib-core.composition); player_control hält nur noch die Action-
--   Bindings und das per-frame Update.
--
--   Caller sets up:
--     composition.define_template{id="player", properties={position,
--         movement_speed, sprite_w, sprite_h, sprite_color, ...}, ...}
--     local p = actor.create{template="player", properties={...}}
--     player_control.bind_movement("move_left", ...)
--     player_control.update(p, dt)  -- jeden Frame
--
--   position.x/.y on the actor is treated as visual CENTER (per Phase-A
--   render-convention). The collision-check uses sprite_w/sprite_h
--   read from the actor's properties.
--
-- Removed in v0.2.0 (use actor.* / composition.* instead):
--   M.set_position / M.position / M.set_size / M.size /
--   M.set_speed / M.speed   — alle obsolete; lese via
--     actor.position(handle) / handle:get_property("sprite_w") /
--     actor.movement_speed(handle).
--
-- DEPRECATED-MVP (unverändert):
--   - separate-axis wall-sliding (fluidity slice)
--   - sprite-rendering (lebt jetzt in render.draw_entities)
--   - click-to-move + drag-select (P.3 RTS slice)
--   - velocity/momentum (juice slice)
--   - collision against maps.walls field (when walls populated)
-- =====================================================================

local maps  = require("lib-core.maps")
local input = require("lib-core.input")
local actor = require("lib-core.actor")

local actions = { left = nil, right = nil, up = nil, down = nil }

local M = {}

function M.bind_movement(left, right, up, down)
    actions.left  = left
    actions.right = right
    actions.up    = up
    actions.down  = down
end

-- 4-corner-AABB-check: returns true iff all 4 corners of the rect
-- centered at (cx, cy) with size (w, h) sit on walkable tiles per
-- maps.is_walkable. cx, cy is the visual center (Phase-A convention).
local function can_occupy_centered(cx, cy, w, h)
    local ts = maps.tile_size()
    local x0 = cx - w / 2
    local y0 = cy - h / 2
    local corners = {
        {x0,           y0},
        {x0 + w - 1,   y0},
        {x0,           y0 + h - 1},
        {x0 + w - 1,   y0 + h - 1},
    }
    for _, c in ipairs(corners) do
        local tx, ty = engine.spatial.pixel_to_tile(c[1], c[2], ts)
        if not maps.is_walkable(tx, ty) then return false end
    end
    return true
end

-- Per-frame input-driven movement. Reads movement-speed + sprite-size
-- from the actor's own properties; applies 4-corner collision check
-- against the current map; commits via actor.move on pass, no-op on
-- blocked (no wall-sliding in v0.2.0).
--
-- Caller is expected to have invoked actor.create + bind_movement
-- before the first update.
function M.update(actor_handle, dt)
    if actor_handle == nil then
        error("player_control.update: actor_handle must not be nil")
    end
    if not actions.left then return end  -- not bound, silent no-op

    local d = input.direction(actions.left, actions.right, actions.up, actions.down)
    if d.x == 0 and d.y == 0 then return end

    local cx, cy = actor.position(actor_handle)
    local speed  = actor.movement_speed(actor_handle)
    local w = actor_handle:get_property("sprite_w")
    local h = actor_handle:get_property("sprite_h")

    local ncx = cx + d.x * speed * dt
    local ncy = cy + d.y * speed * dt

    if can_occupy_centered(ncx, ncy, w, h) then
        actor.move(actor_handle, ncx - cx, ncy - cy)
    end
    -- else: blocked, no movement (no wall-sliding in P.0/v0.2.0)
end

return M