import type { Asset } from '../model/Asset';
import { type AssetType, isPlaceableType } from '../model/AssetTypes';
import {
  type FieldValue,
  isList,
  isStruct,
  type ListValue,
  type PropertyBag,
  type PropertyValue,
  type StructValue,
  textOf,
} from '../model/Properties';
import {
  coerceAs,
  coerceField,
  emptyOf,
  type FieldKind,
  type FlatKind,
  type ValueOf,
  type VariableKind,
} from './kinds';
import { findAssetOf, type Project } from '../model/Project';
import type { SceneObject } from '../model/SceneObject';
import { flatListOf, listItemOf } from './listItems';
import { SHADER_KEY, shaderOf, shaderParamDefs } from './shaders';

/**
 * What a kind's definition carries beyond key, label and default. `decimals` belongs only on
 * properties that are integral by meaning (counts, sizes in whole pixels), not on geometry: dragging
 * produces fractions, and the field rounds the value away rather than hiding it. Without
 * `assetTypes` an asset picker offers every placeable asset.
 */
type Extras<K extends FlatKind> = K extends 'number'
  ? { min?: number; max?: number; step?: number; decimals?: number }
  : K extends 'enum'
    ? { options: { value: string; label: string }[] }
    : K extends 'asset'
      ? { assetTypes?: readonly AssetType[] }
      : unknown;

/** The definition of a flat kind: its default is a value of that kind, as the table says. */
export type FlatDef<K extends FlatKind = FlatKind> = {
  [P in K]: { key: string; label: string; kind: P; default: ValueOf<P> } & Extras<P>;
}[K];

/** The inspector is generated from these entries, so a new property is one line in a schema below. */
export type PropertyDef =
  | FlatDef
  /**
   * A list declares nothing about its items: each one carries its own kind (see `listItems.ts`),
   * and the graph types a list as a list, so one `list` port fits them all. There is no `object`
   * item kind: a list is stored in the project file, and an object is a live handle that no reload
   * survives.
   */
  | { key: string; label: string; kind: 'list'; default: ListValue }
  /**
   * `fields` is the declaration; the value carries exactly those keys, which is what lets a struct
   * keep its shape while single fields are written (`mergeStruct`).
   */
  | { key: string; label: string; kind: 'struct'; default: StructValue; fields: readonly StructFieldDef[] };

export interface PrimitiveFieldDef {
  key: string;
  kind: FieldKind;
}

/** A list held by a struct field. Its items declare nothing either, but they stay flat. */
export interface ListFieldDef {
  key: string;
  kind: 'list';
}

export type StructFieldDef = PrimitiveFieldDef | ListFieldDef;

export type StructDef = Extract<PropertyDef, { kind: 'struct' }>;

export type PropertySchema = readonly PropertyDef[];

/**
 * The definition of a field kind, its default read from `value` (empty when nothing is given). The
 * cast is the table's promise that `coerce` yields the kind.
 */
export function flatDef<K extends FieldKind>(
  key: string,
  kind: K,
  { label = key, value }: { label?: string; value?: PropertyValue } = {},
): FlatDef<K> {
  return { key, label, kind, default: coerceField(value, kind) } as FlatDef<K>;
}

/**
 * Properties every placeable asset has. A disabled object is not drawn, does not collide and its
 * behavior does not run – and the same goes for everything parented below it.
 */
export const COMMON_PROPS: PropertySchema = [
  { key: 'enabled', label: 'Enabled', kind: 'boolean', default: true },
];

const COMMON_KEYS = new Set(COMMON_PROPS.map((d) => d.key));

export function isCommonProp(key: string): boolean {
  return COMMON_KEYS.has(key);
}

/** A field lives inside its struct, so the reserved property keys do not apply to it. */
export function isValidFieldName(name: string): boolean {
  return /^[A-Za-z_][A-Za-z0-9_]*$/.test(name);
}

/** Identifier-like, and not a common property key – a variable "enabled" would shadow the switch. */
export function isValidVariableName(name: string): boolean {
  return isValidFieldName(name) && !isCommonProp(name);
}

/** Position is deliberately absent: it belongs to scene objects, not to asset types. */
const ASSET_SCHEMAS: Record<AssetType, PropertySchema> = {
  scene: [{ key: 'backgroundColor', label: 'Background', kind: 'color', default: 0x2a2d34 }],
  camera: [
    // A view is a pixel raster, so half a pixel of it means nothing.
    { key: 'width', label: 'View width', kind: 'number', default: 640, min: 16, step: 1, decimals: 0 },
    { key: 'height', label: 'View height', kind: 'number', default: 360, min: 16, step: 1, decimals: 0 },
    { key: 'zoom', label: 'Zoom', kind: 'number', default: 1, min: 0.1, max: 10, step: 0.1 },
  ],
  sprite: [
    { key: 'width', label: 'Width', kind: 'number', default: 100, min: 1, step: 1 },
    { key: 'height', label: 'Height', kind: 'number', default: 100, min: 1, step: 1 },
    // The fill while there is no picture, and a tint multiplier once there is one: white = no tint.
    { key: 'color', label: 'Color', kind: 'color', default: 0xffffff },
    { key: 'texture', label: 'Texture', kind: 'texture', default: '' },
    // The shader's own parameters follow this row – see `schemaForAsset`. Empty is no shader at all.
    { key: SHADER_KEY, label: 'Shader', kind: 'asset', default: '', assetTypes: ['shader'] },
  ],
  // The picture itself is intrinsic data on the asset (see TextureAsset), not a property.
  texture: [
    {
      key: 'filter',
      label: 'Filter',
      kind: 'enum',
      default: 'linear',
      options: [
        { value: 'linear', label: 'Linear' },
        { value: 'nearest', label: 'Nearest' },
      ],
    },
  ],
  // The pictures are intrinsic data on the asset (see AnimationAsset).
  animation: [
    { key: 'fps', label: 'Frames per second', kind: 'number', default: 10, min: 0.1, max: 120, step: 1 },
    {
      key: 'playback',
      label: 'Playback',
      kind: 'enum',
      default: 'loop',
      options: [
        { value: 'loop', label: 'Loop' },
        { value: 'once', label: 'Once' },
        { value: 'pingpong', label: 'Ping-pong' },
      ],
    },
  ],
  // Behaviors declare their own properties (variables) per asset too – see `schemaForAsset`.
  behavior: [{ key: 'runInEditor', label: 'Run in editor', kind: 'boolean', default: false }],
  // The states are the asset's graph (see StateMachineAsset), not a property.
  statemachine: [],
  // The nodes are the asset's graph (see ShaderAsset); its parameters are rows of the sprites wearing it.
  shader: [],
  collider: [
    {
      key: 'shape',
      label: 'Shape',
      kind: 'enum',
      default: 'box',
      options: [
        { value: 'box', label: 'Box' },
        { value: 'circle', label: 'Circle' },
      ],
    },
    { key: 'width', label: 'Width', kind: 'number', default: 100, min: 1, step: 1 },
    { key: 'height', label: 'Height', kind: 'number', default: 100, min: 1, step: 1 },
    { key: 'radius', label: 'Radius', kind: 'number', default: 50, min: 1, step: 1 },
    { key: 'isTrigger', label: 'Trigger (no blocking)', kind: 'boolean', default: false },
  ],
  // A container is pure structure: its content is the template, not a property.
  container: [],
  text: [
    { key: 'text', label: 'Text', kind: 'text', default: 'Text' },
    { key: 'fontSize', label: 'Font size', kind: 'number', default: 32, min: 1, step: 1, decimals: 0 },
    { key: 'color', label: 'Color', kind: 'color', default: 0xffffff },
    {
      key: 'align',
      label: 'Align',
      kind: 'enum',
      default: 'center',
      options: [
        { value: 'left', label: 'Left' },
        { value: 'center', label: 'Center' },
        { value: 'right', label: 'Right' },
      ],
    },
  ],
};

const FULL_SCHEMAS: Record<AssetType, PropertySchema> = Object.fromEntries(
  (Object.keys(ASSET_SCHEMAS) as AssetType[]).map((type) => [
    type,
    isPlaceableType(type) ? [...COMMON_PROPS, ...ASSET_SCHEMAS[type]] : ASSET_SCHEMAS[type],
  ]),
) as Record<AssetType, PropertySchema>;

export function schemaFor(type: AssetType): PropertySchema {
  return FULL_SCHEMAS[type];
}

/**
 * The type schema, for behaviors followed by their declared variables, for sprites by the
 * parameters of the shader asset their bag names – which is why the project is needed.
 */
export function schemaForAsset(project: Project, asset: Asset): PropertySchema {
  return schemaForBag(project, asset, asset.props);
}

/** A placed object's rows: a sprite overriding its shader has that shader's parameters. */
export function schemaForObject(project: Project, asset: Asset, object: SceneObject): PropertySchema {
  const shader = object.overrides[SHADER_KEY];
  return schemaForBag(project, asset, shader === undefined ? asset.props : { [SHADER_KEY]: shader });
}

function schemaForBag(project: Project, asset: Asset, bag: PropertyBag): PropertySchema {
  if (asset.type === 'behavior') return [...FULL_SCHEMAS.behavior, ...asset.variables];
  if (asset.type === 'sprite') return [...FULL_SCHEMAS.sprite, ...shaderParamRows(project, shaderOf(bag))];
  return FULL_SCHEMAS[asset.type];
}

/** The rows a shader asset adds to the sprites wearing it; a dangling id adds none. */
export function shaderParamRows(project: Project, shaderId: string): PropertyDef[] {
  const shader = shaderId ? findAssetOf(project, shaderId, 'shader') : undefined;
  return shader ? shaderParamDefs(shader.graph) : [];
}

/** A shader parameter a sprite *may* have, with the shaders that declare it under that name. */
export interface ShaderParamRow {
  def: PropertyDef;
  shaders: string[];
}

/**
 * The parameters of every shader in the project, one row per name – which sprite wears which shader
 * is only known at runtime, so the picker offers them all and names where each one comes from.
 */
export function allShaderParamRows(project: Project): ShaderParamRow[] {
  const rows = new Map<string, ShaderParamRow>();
  for (const asset of project.assets)
    if (asset.type === 'shader')
      for (const def of shaderParamDefs(asset.graph)) {
        const row = rows.get(def.key);
        if (!row) rows.set(def.key, { def, shaders: [asset.name] });
        else if (!row.shaders.includes(asset.name)) row.shaders.push(asset.name);
      }
  return [...rows.values()];
}

export function propDef(project: Project, asset: Asset, key: string): PropertyDef | undefined {
  return schemaForAsset(project, asset).find((d) => d.key === key);
}

/** A fresh bag of the type's default values (callers may mutate it). */
export function defaultsFor(type: AssetType): PropertyBag {
  return defaultsOf(FULL_SCHEMAS[type]);
}

export function defaultsOf(schema: PropertySchema): PropertyBag {
  const bag: PropertyBag = {};
  for (const def of schema) bag[def.key] = def.default;
  return bag;
}

export function variableDef(
  key: string,
  kind: VariableKind,
  defaultValue?: PropertyValue,
  fields?: readonly StructFieldDef[],
): PropertyDef {
  switch (kind) {
    case 'list':
      return { key, label: key, kind, default: (isList(defaultValue) ? defaultValue : []).map(listItemOf) };
    case 'struct': {
      const declared = fields ?? [];
      return { key, label: key, kind, fields: declared, default: structOf(declared, defaultValue) };
    }
    default:
      return flatDef(key, kind, { value: defaultValue });
  }
}

/** The empty value of a kind, so a field that is not there yet still has one. */
export function emptyFieldValue(field: StructFieldDef): FieldValue {
  return field.kind === 'list' ? [] : emptyOf(field.kind);
}

/**
 * A struct over exactly the declared fields: a declared field missing from `from` starts empty
 * rather than absent, so a struct value always has the shape its declaration promises.
 */
export function structOf(fields: readonly StructFieldDef[], from: PropertyValue | undefined): StructValue {
  const source = isStruct(from) ? from : {};
  const value: Record<string, FieldValue> = {};
  for (const field of fields)
    value[field.key] =
      field.key in source ? coerceFieldValue(source[field.key]!, field) : emptyFieldValue(field);
  return value;
}

export function coerceValue(def: PropertyDef, value: PropertyValue): PropertyValue {
  switch (def.kind) {
    case 'number': {
      let n = coerceAs(value, def.kind, def.default);
      if (def.min !== undefined) n = Math.max(def.min, n);
      if (def.max !== undefined) n = Math.min(def.max, n);
      return n;
    }
    case 'enum': {
      const s = textOf(value);
      return def.options.some((o) => o.value === s) ? s : def.default;
    }
    case 'list':
      // Each item keeps the kind it arrived as; there is no declaration to force it into.
      return isList(value) ? value.map(listItemOf) : def.default;
    case 'struct':
      return structOf(def.fields, value);
    default:
      return coerceAs(value, def.kind, def.default);
  }
}

/** A struct field as its declaration promises. A list field takes only a list – see `ListFieldDef`. */
export function coerceFieldValue(value: PropertyValue, field: StructFieldDef): FieldValue {
  return field.kind === 'list' ? flatListOf(value) : coerceField(value, field.kind);
}