import { html } from "lit";
import { customElement, state } from "lit/decorators.js";
import {
  GitDiffFile,
  GitDataService,
  DefaultGitDataService,
} from "./git-data-service";
import "./sketch-monaco-view";
import { SketchTailwindElement } from "./sketch-tailwind-element";

@customElement("mobile-diff")
export class MobileDiff extends SketchTailwindElement {
  private gitService: GitDataService = new DefaultGitDataService();

  @state()
  private files: GitDiffFile[] = [];

  @state()
  private fileContents: Map<string, { original: string; modified: string }> =
    new Map();

  @state()
  private loading: boolean = false;

  @state()
  private error: string | null = null;

  @state()
  private baseCommit: string = "";

  @state()
  private fileExpandStates: Map<string, boolean> = new Map();

  connectedCallback() {
    super.connectedCallback();
    this.loadDiffData();
  }

  private async loadDiffData() {
    this.loading = true;
    this.error = null;
    this.files = [];
    this.fileContents.clear();

    try {
      // Get base commit reference
      this.baseCommit = await this.gitService.getBaseCommitRef();

      // Get diff from base commit to untracked changes (empty string for working directory)
      this.files = await this.gitService.getDiff(this.baseCommit, "");

      // Ensure files is always an array
      if (!this.files) {
        this.files = [];
      }

      if (this.files.length > 0) {
        await this.loadAllFileContents();
      }
    } catch (error) {
      console.error("Error loading diff data:", error);
      this.error = `Error loading diff: ${error instanceof Error ? error.message : String(error)}`;
      // Ensure files is always an array even on error
      this.files = [];
    } finally {
      this.loading = false;
    }
  }

  private async loadAllFileContents() {
    try {
      const promises = this.files.map(async (file) => {
        try {
          let originalCode = "";
          let modifiedCode = "";

          // Load original content (from the base commit)
          if (file.status !== "A") {
            // For modified, renamed, or deleted files: load original content
            originalCode = await this.gitService.getFileContent(
              file.old_hash || "",
            );
          }

          // Load modified content (from working directory)
          if (file.status === "D") {
            // Deleted file: empty modified content
            modifiedCode = "";
          } else {
            // Added/modified/renamed: use working copy content
            try {
              modifiedCode = await this.gitService.getWorkingCopyContent(
                file.path,
              );
            } catch (error) {
              console.warn(
                `Could not get working copy for ${file.path}:`,
                error,
              );
              modifiedCode = "";
            }
          }

          this.fileContents.set(file.path, {
            original: originalCode,
            modified: modifiedCode,
          });
        } catch (error) {
          console.error(`Error loading content for file ${file.path}:`, error);
          // Store empty content for failed files
          this.fileContents.set(file.path, {
            original: "",
            modified: "",
          });
        }
      });

      await Promise.all(promises);
    } catch (error) {
      console.error("Error loading file contents:", error);
      throw error;
    }
  }

  private getFileStatusClass(status: string): string {
    switch (status.toUpperCase()) {
      case "A":
        return "added";
      case "M":
        return "modified";
      case "D":
        return "deleted";
      case "R":
      default:
        if (status.toUpperCase().startsWith("R")) {
          return "renamed";
        }
        return "modified";
    }
  }

  private getFileStatusTailwindClass(status: string): string {
    switch (status.toUpperCase()) {
      case "A":
        return "bg-green-100 text-green-800";
      case "M":
        return "bg-yellow-100 text-yellow-800";
      case "D":
        return "bg-red-100 text-red-800";
      case "R":
      default:
        if (status.toUpperCase().startsWith("R")) {
          return "bg-blue-100 text-blue-800";
        }
        return "bg-yellow-100 text-yellow-800";
    }
  }

  private getFileStatusText(status: string): string {
    switch (status.toUpperCase()) {
      case "A":
        return "Added";
      case "M":
        return "Modified";
      case "D":
        return "Deleted";
      case "R":
      default:
        if (status.toUpperCase().startsWith("R")) {
          return "Renamed";
        }
        return "Modified";
    }
  }

  private getChangesInfo(file: GitDiffFile): string {
    const additions = file.additions || 0;
    const deletions = file.deletions || 0;

    if (additions === 0 && deletions === 0) {
      return "";
    }

    const parts = [];
    if (additions > 0) {
      parts.push(`+${additions}`);
    }
    if (deletions > 0) {
      parts.push(`-${deletions}`);
    }

    return `(${parts.join(", ")})`;
  }

  private getPathInfo(file: GitDiffFile): string {
    if (file.old_path && file.old_path !== "") {
      // For renames, show old_path → new_path
      return `${file.old_path} → ${file.path}`;
    }
    // For regular files, just show the path
    return file.path;
  }

  private toggleFileExpansion(filePath: string) {
    const currentState = this.fileExpandStates.get(filePath) ?? false;
    const newState = !currentState;
    this.fileExpandStates.set(filePath, newState);

    // Apply to the specific Monaco view component for this file
    const monacoView = this.querySelector(
      `sketch-monaco-view[data-file-path="${filePath}"]`,
    );
    if (monacoView) {
      (monacoView as any).toggleHideUnchangedRegions(!newState); // inverted because true means "hide unchanged"
    }

    // Force a re-render to update the button state
    this.requestUpdate();
  }

  private renderExpandAllIcon() {
    return html`
      <svg width="16" height="16" viewBox="0 0 16 16" fill="currentColor">
        <!-- Dotted line in the middle -->
        <line
          x1="2"
          y1="8"
          x2="14"
          y2="8"
          stroke="currentColor"
          stroke-width="1"
          stroke-dasharray="2,1"
        />
        <!-- Large arrow pointing up -->
        <path d="M8 2 L5 6 L11 6 Z" fill="currentColor" />
        <!-- Large arrow pointing down -->
        <path d="M8 14 L5 10 L11 10 Z" fill="currentColor" />
      </svg>
    `;
  }

  private renderCollapseIcon() {
    return html`
      <svg width="16" height="16" viewBox="0 0 16 16" fill="currentColor">
        <!-- Dotted line in the middle -->
        <line
          x1="2"
          y1="8"
          x2="14"
          y2="8"
          stroke="currentColor"
          stroke-width="1"
          stroke-dasharray="2,1"
        />
        <!-- Large arrow pointing down towards line -->
        <path d="M8 6 L5 2 L11 2 Z" fill="currentColor" />
        <!-- Large arrow pointing up towards line -->
        <path d="M8 10 L5 14 L11 14 Z" fill="currentColor" />
      </svg>
    `;
  }

  private renderFileDiff(file: GitDiffFile) {
    const content = this.fileContents.get(file.path);
    const isExpanded = this.fileExpandStates.get(file.path) ?? false;

    if (!content) {
      return html`
        <div class="mb-4 last:mb-0">
          <div
            class="bg-gray-50 border border-gray-200 border-b-0 p-3 font-mono text-sm font-medium text-gray-700 sticky top-0 z-10 flex items-center justify-between"
          >
            <div class="flex items-center">
              <span
                class="inline-block px-1.5 py-0.5 rounded text-xs font-bold mr-2 font-sans ${this.getFileStatusTailwindClass(
                  file.status,
                )}"
              >
                ${this.getFileStatusText(file.status)}
              </span>
              ${this.getPathInfo(file)}
              ${this.getChangesInfo(file)
                ? html`<span class="ml-2 text-xs text-gray-500"
                    >${this.getChangesInfo(file)}</span
                  >`
                : ""}
            </div>
            <button class="text-gray-400" disabled>
              ${this.renderExpandAllIcon()}
            </button>
          </div>
          <div
            class="border border-gray-200 border-t-0 min-h-[200px] overflow-hidden bg-white"
          >
            <div
              class="flex items-center justify-center h-full text-base text-gray-500 text-center p-5"
            >
              Loading ${file.path}...
            </div>
          </div>
        </div>
      `;
    }

    return html`
      <div class="mb-4 last:mb-0">
        <div
          class="bg-gray-50 border border-gray-200 border-b-0 p-3 font-mono text-sm font-medium text-gray-700 sticky top-0 z-10 flex items-center justify-between"
        >
          <div class="flex items-center">
            <span
              class="inline-block px-1.5 py-0.5 rounded text-xs font-bold mr-2 font-sans ${this.getFileStatusTailwindClass(
                file.status,
              )}"
            >
              ${this.getFileStatusText(file.status)}
            </span>
            ${this.getPathInfo(file)}
            ${this.getChangesInfo(file)
              ? html`<span class="ml-2 text-xs text-gray-500"
                  >${this.getChangesInfo(file)}</span
                >`
              : ""}
          </div>
          <button
            class="text-gray-600 hover:text-gray-800 p-1 rounded"
            @click="${() => this.toggleFileExpansion(file.path)}"
            title="${isExpanded
              ? "Collapse: Hide unchanged regions to focus on changes"
              : "Expand: Show all lines including unchanged regions"}"
          >
            ${isExpanded
              ? this.renderCollapseIcon()
              : this.renderExpandAllIcon()}
          </button>
        </div>
        <div
          class="border border-gray-200 border-t-0 min-h-[200px] overflow-hidden bg-white"
        >
          <sketch-monaco-view
            class="w-full min-h-[200px]"
            .originalCode="${content.original}"
            .modifiedCode="${content.modified}"
            .originalFilename="${file.path}"
            .modifiedFilename="${file.path}"
            ?readOnly="true"
            ?inline="true"
            data-file-path="${file.path}"
          ></sketch-monaco-view>
        </div>
      </div>
    `;
  }

  render() {
    return html`
      <div class="flex flex-col h-full min-h-0 overflow-hidden bg-white">
        <div
          class="flex-1 overflow-auto min-h-0"
          style="-webkit-overflow-scrolling: touch;"
        >
          ${this.loading
            ? html`<div
                class="flex items-center justify-center h-full text-base text-gray-500 text-center p-5"
              >
                Loading diff...
              </div>`
            : this.error
              ? html`<div
                  class="flex items-center justify-center h-full text-base text-red-600 text-center p-5"
                >
                  ${this.error}
                </div>`
              : !this.files || this.files.length === 0
                ? html`<div
                    class="flex items-center justify-center h-full text-base text-gray-500 text-center p-5"
                  >
                    No changes to show
                  </div>`
                : this.files.map((file) => this.renderFileDiff(file))}
        </div>
      </div>
    `;
  }
}

declare global {
  interface HTMLElementTagNameMap {
    "mobile-diff": MobileDiff;
  }
}