"use client";

import { create } from "zustand";
import {
  addLayer,
  createLayer,
  createProject,
  parseProjectFile,
  removeLayer,
  reorderLayer,
  serializeProjectFile,
  setCanvasSize as applyCanvasSize,
  setLayerEffect,
  removeLayerEffect,
  setLayerVisible,
  setEffectEnabled,
  updateLayerTransform,
  normalizeProject,
  getAllTools,
  type EditorToolId,
} from "@pien-studio/editor-core";
import {
  getAssetRefId,
  getLayerAssetRef,
  getLayerRuntimeSource,
  type Layer,
  type LayerEffect,
  type LayerType,
  type Project,
} from "@pien-studio/types";
import { localProjectRepository } from "../lib/project-repository";
import { DEFAULT_IMAGE_IMPORT, MIN_LAYER_SIZE } from "../lib/editor-constants";
import { hasProjectChanged } from "../lib/project-equality";
import {
  capHistory,
  cloneLayer,
  cloneProject,
  computeHistoryFlags,
  makeHistory,
  resolveSelectedLayerId,
  type HistoryState,
} from "./editor-store-helpers";

const DRAFT_TRANSFORM_EPSILON = 0.01;

export { EditorToolId };

const allTools = getAllTools();
export const EDITOR_TOOLS = Object.fromEntries(
  allTools.map((t) => [t.id, t]),
) as Record<string, (typeof allTools)[number]>;

type TransactionState = {
  baselineProject: Project;
  baselineSelectedLayerId: string | null;
};

type EditorState = {
  project: Project;
  selectedLayerId: string | null;
  tool: EditorToolId;
  history: HistoryState;
  canUndo: boolean;
  canRedo: boolean;
  clipboardLayer: Layer | null;
  isDirty: boolean;
  transaction: TransactionState | null;
  startTransaction: () => void;
  commitTransaction: () => void;
  cancelTransaction: () => void;
  applyProjectDraft: (project: Project) => void;
  setTool: (tool: EditorToolId) => void;
  addLayerByType: (type: LayerType) => void;
  setSelectedLayerPosition: (x: number, y: number) => void;
  setSelectedLayerPositionDraft: (x: number, y: number) => void;
  setSelectedLayerSize: (width: number, height: number) => void;
  setSelectedLayerSizeDraft: (width: number, height: number) => void;
  setSelectedLayerRotation: (rotation: number) => void;
  setSelectedLayerRotationDraft: (rotation: number) => void;
  removeSelectedLayer: () => void;
  moveSelectedLayerOrder: (direction: "up" | "down") => void;
  selectLayer: (layerId: string | null) => void;
  copySelectedLayer: () => void;
  cutSelectedLayer: () => void;
  pasteLayer: (e?: ClipboardEvent) => void;
  resetProject: () => void;
  saveCurrentProject: () => Promise<void>;
  loadProjectById: (projectId: string) => Promise<boolean>;
  setProject: (project: Project) => void;
  importProjectFromJson: (raw: string) => { ok: boolean; error?: string };
  addCanvasSizedLayer: (sourceUri: string, name?: string) => void;
  importImageFromFile: (file: File) => Promise<void>;
  updateImageLayerSource: (layerId: string, sourceUri: string) => void;
  setLayerEffect: (layerId: string, effect: LayerEffect) => void;
  removeLayerEffect: (layerId: string, kind: LayerEffect["kind"]) => void;
  setLayerVisible: (layerId: string, visible: boolean) => void;
  setEffectEnabled: (
    layerId: string,
    kind: LayerEffect["kind"],
    enabled: boolean,
  ) => void;
  setCanvasSize: (width: number, height: number) => void;
  exportProjectToJson: () => string;
  undo: () => void;
  redo: () => void;
  jumpToPast: (idx: number) => void;
  jumpToFuture: (idx: number) => void;
};

const initialProject = createProject("Untitled Project");

function withCommittedProject(
  state: EditorState,
  nextProject: Project,
  extras?: Partial<EditorState>,
) {
  const past = capHistory([...state.history.past, state.history.present]);
  const history = { past, present: cloneProject(nextProject), future: [] };
  return {
    project: nextProject,
    history,
    selectedLayerId: resolveSelectedLayerId(nextProject, state.selectedLayerId),
    transaction: null,
    ...computeHistoryFlags(history),
    isDirty: true,
    ...extras,
  } satisfies Partial<EditorState>;
}

function makeStableProjectState(
  previousSelectedLayerId: string | null,
  project: Project,
) {
  const history = makeHistory(project);
  return {
    project,
    selectedLayerId: resolveSelectedLayerId(project, previousSelectedLayerId),
    history,
    ...computeHistoryFlags(history),
    clipboardLayer: null,
    transaction: null,
    isDirty: false,
  };
}

function getProjectAssetIds(project: Project): string[] {
  return project.layers
    .map((layer) => getAssetRefId(getLayerAssetRef(layer)))
    .filter((assetId): assetId is string => Boolean(assetId));
}

export const useEditorStore = create<EditorState>((set, get) => ({
  project: initialProject,
  selectedLayerId: null,
  tool: "pointer",
  history: makeHistory(initialProject),
  ...computeHistoryFlags(makeHistory(initialProject)),
  clipboardLayer: null,
  isDirty: false,
  transaction: null,

  startTransaction: () =>
    set((state) => {
      if (state.transaction) return state;
      return {
        transaction: {
          baselineProject: cloneProject(state.project),
          baselineSelectedLayerId: state.selectedLayerId,
        },
      };
    }),

  commitTransaction: () =>
    set((state) => {
      if (!state.transaction) return state;
      if (
        !hasProjectChanged(state.transaction.baselineProject, state.project)
      ) {
        return { transaction: null };
      }

      const past = capHistory([
        ...state.history.past,
        cloneProject(state.transaction.baselineProject),
      ]);
      const history = {
        past,
        present: cloneProject(state.project),
        future: [],
      };
      return {
        history,
        transaction: null,
        ...computeHistoryFlags(history),
        isDirty: true,
      };
    }),

  cancelTransaction: () =>
    set((state) => {
      if (!state.transaction) return state;
      return {
        project: cloneProject(state.transaction.baselineProject),
        selectedLayerId: resolveSelectedLayerId(
          state.transaction.baselineProject,
          state.transaction.baselineSelectedLayerId,
        ),
        transaction: null,
      };
    }),

  applyProjectDraft: (project) => set(() => ({ project })),

  setTool: (tool) => {
    if (!EDITOR_TOOLS[tool]) return;
    set({ tool });
  },

  addLayerByType: (type) =>
    set((state) => {
      const layer = createLayer(type);
      const nextProject = addLayer(state.project, layer);
      return withCommittedProject(state, nextProject, {
        selectedLayerId: layer.id,
      });
    }),

  addCanvasSizedLayer: (sourceUri, name) =>
    set((state) => {
      const { width, height } = state.project.canvas;
      const layer = createLayer("raster", {
        name: name ?? "Layer",
        asset: { kind: "inline", uri: sourceUri },
        x: 0,
        y: 0,
        width,
        height,
      });
      const nextProject = addLayer(state.project, layer);
      return withCommittedProject(state, nextProject, {
        selectedLayerId: layer.id,
      });
    }),

  setSelectedLayerPosition: (x, y) =>
    set((state) => {
      if (!state.selectedLayerId) return state;
      const committed = state.history.present.layers.find(
        (layer) => layer.id === state.selectedLayerId,
      );
      if (committed && committed.x === x && committed.y === y) return state;
      const nextProject = updateLayerTransform(
        state.project,
        state.selectedLayerId,
        { x, y },
      );
      return withCommittedProject(state, nextProject);
    }),

  setSelectedLayerPositionDraft: (x, y) =>
    set((state) => {
      if (!state.selectedLayerId) return state;
      if (!Number.isFinite(x) || !Number.isFinite(y)) return state;
      const current = state.project.layers.find(
        (layer) => layer.id === state.selectedLayerId,
      );
      if (current && current.x === x && current.y === y) return state;
      return {
        project: updateLayerTransform(state.project, state.selectedLayerId, {
          x,
          y,
        }),
      };
    }),

  setSelectedLayerSize: (width, height) =>
    set((state) => {
      if (!state.selectedLayerId) return state;
      const committed = state.history.present.layers.find(
        (layer) => layer.id === state.selectedLayerId,
      );
      if (committed && committed.width === width && committed.height === height)
        return state;
      return withCommittedProject(
        state,
        updateLayerTransform(state.project, state.selectedLayerId, {
          width,
          height,
        }),
      );
    }),

  setSelectedLayerSizeDraft: (width, height) =>
    set((state) => {
      if (!state.selectedLayerId) return state;
      if (!Number.isFinite(width) || !Number.isFinite(height)) return state;
      const current = state.project.layers.find(
        (layer) => layer.id === state.selectedLayerId,
      );
      const nextWidth = Math.max(MIN_LAYER_SIZE, width);
      const nextHeight = Math.max(MIN_LAYER_SIZE, height);

      if (current) {
        const currentWidth = current.width;
        const currentHeight = current.height;

        if (
          typeof currentWidth === "number" &&
          typeof currentHeight === "number" &&
          Math.abs(currentWidth - nextWidth) < DRAFT_TRANSFORM_EPSILON &&
          Math.abs(currentHeight - nextHeight) < DRAFT_TRANSFORM_EPSILON
        ) {
          return state;
        }
      }
      return {
        project: updateLayerTransform(state.project, state.selectedLayerId, {
          width: nextWidth,
          height: nextHeight,
        }),
      };
    }),

  removeSelectedLayer: () =>
    set((state) => {
      if (!state.selectedLayerId) return state;
      const nextProject = removeLayer(state.project, state.selectedLayerId);
      return withCommittedProject(state, nextProject);
    }),

  moveSelectedLayerOrder: (direction) =>
    set((state) => {
      if (!state.selectedLayerId) return state;
      const idx = state.project.layers.findIndex(
        (layer) => layer.id === state.selectedLayerId,
      );
      if (idx < 0) return state;
      const nextIndex = direction === "up" ? idx + 1 : idx - 1;
      return withCommittedProject(
        state,
        reorderLayer(state.project, state.selectedLayerId, nextIndex),
      );
    }),

  selectLayer: (layerId) =>
    set((state) => ({
      selectedLayerId: resolveSelectedLayerId(state.project, layerId),
    })),

  setSelectedLayerRotation: (rotation) =>
    set((state) => {
      if (!state.selectedLayerId) return state;
      const committed = state.history.present.layers.find(
        (layer) => layer.id === state.selectedLayerId,
      );
      if (committed && committed.rotation === rotation) return state;
      return withCommittedProject(
        state,
        updateLayerTransform(state.project, state.selectedLayerId, {
          rotation,
        }),
      );
    }),

  setSelectedLayerRotationDraft: (rotation) =>
    set((state) => {
      if (!state.selectedLayerId) return state;
      const current = state.project.layers.find(
        (layer) => layer.id === state.selectedLayerId,
      );
      if (current && current.rotation === rotation) return state;
      return {
        project: updateLayerTransform(state.project, state.selectedLayerId, {
          rotation,
        }),
      };
    }),

  copySelectedLayer: () =>
    set((state) => {
      if (!state.selectedLayerId) return state;
      const layer = state.project.layers.find(
        (item) => item.id === state.selectedLayerId,
      );
      if (!layer) return state;
      return { clipboardLayer: cloneLayer(layer) };
    }),

  cutSelectedLayer: () =>
    set((state) => {
      if (!state.selectedLayerId) return state;
      const layer = state.project.layers.find(
        (item) => item.id === state.selectedLayerId,
      );
      if (!layer) return state;
      const nextProject = removeLayer(state.project, state.selectedLayerId);
      return withCommittedProject(state, nextProject, {
        clipboardLayer: cloneLayer(layer),
      });
    }),

  pasteLayer: (e?: ClipboardEvent) => {
    const state = get();

    if (state.clipboardLayer) {
      const base = state.clipboardLayer;
      const pasted: Layer = {
        ...base,
        id: crypto.randomUUID(),
        x: base.x + 20,
        y: base.y + 20,
      };
      set((s) =>
        withCommittedProject(s, addLayer(s.project, pasted), {
          selectedLayerId: pasted.id,
        }),
      );
      return;
    }

    async function pasteImageBlob(blob: Blob) {
      const reader = new FileReader();
      const dataUrl = await new Promise<string>((resolve, reject) => {
        reader.onload = () =>
          resolve(typeof reader.result === "string" ? reader.result : "");
        reader.onerror = reject;
        reader.readAsDataURL(blob);
      });
      const imageSize = await new Promise<{ width: number; height: number }>(
        (resolve) => {
          const image = new Image();
          image.onload = () =>
            resolve({ width: image.naturalWidth, height: image.naturalHeight });
          image.onerror = () =>
            resolve({
              width: DEFAULT_IMAGE_IMPORT.fallbackWidth,
              height: DEFAULT_IMAGE_IMPORT.fallbackHeight,
            });
          image.src = dataUrl;
        },
      );
      const layer = createLayer("raster", {
        name: "Image",
        asset: { kind: "inline", uri: dataUrl },
        x: DEFAULT_IMAGE_IMPORT.offsetX,
        y: DEFAULT_IMAGE_IMPORT.offsetY,
        width: Math.max(1, Math.round(imageSize.width)),
        height: Math.max(1, Math.round(imageSize.height)),
      });
      set((s) =>
        withCommittedProject(s, addLayer(s.project, layer), {
          selectedLayerId: layer.id,
        }),
      );
    }

    // Prefer event clipboard data to avoid permission prompts.
    if (e?.clipboardData) {
      for (const item of Array.from(e.clipboardData.items)) {
        if (item.type.startsWith("image/")) {
          const blob = item.getAsFile();
          if (blob) {
            void pasteImageBlob(blob);
            return;
          }
        }
      }
      return;
    }

    // Async Clipboard API is a fallback because browser support and permissions vary.
    navigator.clipboard
      .read()
      .then(async (clipboardItems) => {
        for (const item of clipboardItems) {
          for (const type of item.types) {
            if (type.startsWith("image/")) {
              const blob = await item.getType(type);
              await pasteImageBlob(blob);
              return;
            }
          }
        }
      })
      .catch(() => {});
  },

  resetProject: () => {
    localProjectRepository.releaseObjectUrls(get().project);
    const project = createProject("Untitled Project");
    const history = makeHistory(project);
    set({
      project,
      selectedLayerId: null,
      history,
      ...computeHistoryFlags(history),
      clipboardLayer: null,
      transaction: null,
      isDirty: false,
    });
  },

  saveCurrentProject: async () => {
    await localProjectRepository.upsertProject(normalizeProject(get().project));
    set({ isDirty: false });
  },

  loadProjectById: async (projectId) => {
    const project = await localProjectRepository.getProject(projectId);
    if (!project) return false;
    const normalized = normalizeProject(project);
    localProjectRepository.releaseObjectUrls(
      get().project,
      getProjectAssetIds(normalized),
    );
    set(makeStableProjectState(get().selectedLayerId, normalized));
    return true;
  },

  setProject: (project) => {
    const normalized = normalizeProject(project);
    localProjectRepository.releaseObjectUrls(
      get().project,
      getProjectAssetIds(normalized),
    );
    set(makeStableProjectState(get().selectedLayerId, normalized));
  },

  importProjectFromJson: (raw) => {
    const parsed = parseProjectFile(raw);
    if (!parsed.ok) return { ok: false, error: parsed.error };
    const normalized = normalizeProject(parsed.project);
    localProjectRepository.releaseObjectUrls(
      get().project,
      getProjectAssetIds(normalized),
    );
    set(makeStableProjectState(get().selectedLayerId, normalized));
    return { ok: true };
  },

  exportProjectToJson: () => {
    const project = normalizeProject(get().project);
    const history = get().history;
    return serializeProjectFile(project, {
      checkpointCount: history.past.length + history.future.length,
    });
  },

  importImageFromFile: async (file) => {
    const reader = new FileReader();
    const dataUrl = await new Promise<string>((resolve, reject) => {
      reader.onload = () =>
        resolve(typeof reader.result === "string" ? reader.result : "");
      reader.onerror = reject;
      reader.readAsDataURL(file);
    });
    const name = file.name.replace(/\.[^/.]+$/, "") || "Image";
    const imageSize = await new Promise<{ width: number; height: number }>(
      (resolve) => {
        const image = new Image();
        image.onload = () =>
          resolve({ width: image.naturalWidth, height: image.naturalHeight });
        image.onerror = () =>
          resolve({
            width: DEFAULT_IMAGE_IMPORT.fallbackWidth,
            height: DEFAULT_IMAGE_IMPORT.fallbackHeight,
          });
        image.src = dataUrl;
      },
    );
    const layer = createLayer("raster", {
      name,
      asset: { kind: "inline", uri: dataUrl },
      x: DEFAULT_IMAGE_IMPORT.offsetX,
      y: DEFAULT_IMAGE_IMPORT.offsetY,
      width: Math.max(1, Math.round(imageSize.width)),
      height: Math.max(1, Math.round(imageSize.height)),
    });

    set((state) =>
      withCommittedProject(state, addLayer(state.project, layer), {
        selectedLayerId: layer.id,
      }),
    );
  },

  updateImageLayerSource: (layerId, sourceUri) =>
    set((state) => {
      if (!sourceUri) return state;
      const layer = state.project.layers.find((item) => item.id === layerId);
      if (!layer || layer.type !== "raster") return state;
      const currentSource = getLayerRuntimeSource(layer);
      if (currentSource === sourceUri) return state;
      const nextProject = updateLayerTransform(state.project, layerId, {
        asset: { kind: "inline", uri: sourceUri },
        runtimeSourceUri: undefined,
      });
      return withCommittedProject(state, nextProject);
    }),

  setLayerEffect: (layerId, effect) =>
    set((state) => {
      const layer = state.project.layers.find((item) => item.id === layerId);
      if (!layer) return state;
      return withCommittedProject(
        state,
        setLayerEffect(state.project, layerId, effect),
      );
    }),

  removeLayerEffect: (layerId, kind) =>
    set((state) => {
      const layer = state.project.layers.find((item) => item.id === layerId);
      if (!layer) return state;
      return withCommittedProject(
        state,
        removeLayerEffect(state.project, layerId, kind),
      );
    }),

  setLayerVisible: (layerId, visible) =>
    set((state) =>
      withCommittedProject(
        state,
        setLayerVisible(state.project, layerId, visible),
      ),
    ),

  setEffectEnabled: (layerId, kind, enabled) =>
    set((state) =>
      withCommittedProject(
        state,
        setEffectEnabled(state.project, layerId, kind, enabled),
      ),
    ),

  setCanvasSize: (width, height) =>
    set((state) =>
      withCommittedProject(
        state,
        applyCanvasSize(state.project, width, height),
      ),
    ),

  undo: () =>
    set((state) => {
      if (state.history.past.length === 0) return state;
      const past = [...state.history.past];
      const previous = past.pop();
      if (!previous) return state;
      const future = [state.history.present, ...state.history.future];
      const history = { past, present: cloneProject(previous), future };
      return {
        project: cloneProject(previous),
        history,
        selectedLayerId: resolveSelectedLayerId(
          previous,
          state.selectedLayerId,
        ),
        transaction: null,
        ...computeHistoryFlags(history),
        isDirty: true,
      };
    }),

  redo: () =>
    set((state) => {
      if (state.history.future.length === 0) return state;
      const future = [...state.history.future];
      const next = future.shift();
      if (!next) return state;
      const past = capHistory([...state.history.past, state.history.present]);
      const history = { past, present: cloneProject(next), future };
      return {
        project: cloneProject(next),
        history,
        selectedLayerId: resolveSelectedLayerId(next, state.selectedLayerId),
        transaction: null,
        ...computeHistoryFlags(history),
        isDirty: true,
      };
    }),

  jumpToPast: (idx) =>
    set((state) => {
      const targetPastLength = Math.max(
        0,
        Math.min(state.history.past.length, idx - 1),
      );
      if (state.history.past.length === targetPastLength) return state;
      const moved = state.history.past.slice(targetPastLength);
      if (moved.length === 0) return state;
      const previous = moved[0];
      if (!previous) return state;
      const past = state.history.past.slice(0, targetPastLength);
      const future = [
        state.history.present,
        ...moved.slice(1),
        ...state.history.future,
      ];
      const history = { past, present: cloneProject(previous), future };
      return {
        project: cloneProject(previous),
        history,
        selectedLayerId: resolveSelectedLayerId(
          previous,
          state.selectedLayerId,
        ),
        transaction: null,
        ...computeHistoryFlags(history),
        isDirty: true,
      };
    }),

  jumpToFuture: (idx) =>
    set((state) => {
      const targetFutureLength = Math.max(
        0,
        Math.min(state.history.future.length, idx),
      );
      if (state.history.future.length === targetFutureLength) return state;
      const redoCount = state.history.future.length - targetFutureLength;
      const next = state.history.future[redoCount - 1];
      if (!next) return state;
      const consumedFuture = state.history.future.slice(0, redoCount - 1);
      const future = state.history.future.slice(redoCount);
      const past = capHistory([
        ...state.history.past,
        state.history.present,
        ...consumedFuture,
      ]);
      const history = { past, present: cloneProject(next), future };
      return {
        project: cloneProject(next),
        history,
        selectedLayerId: resolveSelectedLayerId(next, state.selectedLayerId),
        transaction: null,
        ...computeHistoryFlags(history),
        isDirty: true,
      };
    }),
}));