import type { Plugin } from "@opencode-ai/plugin";
import { existsSync, readFileSync } from "node:fs";
import path from "node:path";
import { fileURLToPath, pathToFileURL } from "node:url";
import { loadConfig, resolveSharingEnabled } from "@plannotator/shared/config";
import { readImprovementHook } from "@plannotator/shared/improvement-hooks";
import { composeImproveContext } from "@plannotator/shared/pfm-reminder";
import { composeSystemPrompt, stripConflictingPlanModeRules } from "./plan-mode";
import {
  isPlanningAgent,
  normalizeWorkflowOptions,
  shouldInjectFullPlanningPrompt,
  shouldInjectGenericPlanReminder,
  shouldModifyPrompts,
  shouldRegisterSubmitPlan,
  type PlannotatorOpenCodeOptions,
  type RuntimeMode,
} from "./workflow";
import {
  runCliPlanReview,
  type OpenCodeBridgeAgent,
  type OpenCodeBridgeContext,
  type OpenCodePlanReviewResult,
} from "./cli-bridge";
import { switchV2SessionAgent } from "./agent-switch";
import { registerNativeCommands } from "./native-commands";
import {
  createV2BridgeClient,
  formatSessionUrlNotice,
  normalizeAgentList,
  type V2ContextLike,
} from "./v2-client";
import { executeSubmitPlan } from "./submit-plan-executor";
import type { PlanEdit } from "./plan-edits";
import { getPlanningPrompt } from "./planning-prompt";

const DEFAULT_PLAN_TIMEOUT_SECONDS = 345_600;
const moduleDir = path.dirname(fileURLToPath(import.meta.url));
let planHtml: string | undefined;

type V2Client = {
  app: {
    agents: () => Promise<{ data: OpenCodeBridgeAgent[] }>;
    log: (entry: { level: "info" | "error"; message: string }) => void;
  };
  /**
   * Visible delivery for the session URL, present only when the host can post
   * a transcript notice. `cli-bridge` prefers it over the (absent on V2) toast
   * for the CLI runtime; `createPlanReadyNotifier` is the embedded runtime's
   * equivalent. See `createSessionUrlNotifier` in `v2-client.ts`.
   */
  notifyUrl?: (input: { url: string; message: string }) => Promise<unknown>;
};

type EmbeddedRuntimeModule = {
  runEmbeddedPlanReview: (input: {
    client: V2Client;
    planContent: string;
    sharingEnabled: boolean;
    shareBaseUrl?: string;
    pasteApiUrl?: string;
    htmlContent: string;
    timeoutSeconds: number | null;
    abortSignal?: AbortSignal;
    logReady: (url: string, isRemote: boolean, port: number) => void;
  }) => Promise<OpenCodePlanReviewResult>;
};

// `Plugin.define` is an identity function in @opencode-ai/plugin; keeping the import
// type-only avoids shipping a runtime dependency on an exact prerelease nightly.
const serverPlugin = {
  id: "plannotator",
  setup: async (ctx) => {
    const workflowOptions = normalizeWorkflowOptions(ctx.options as PlannotatorOpenCodeOptions);
    let cachedAgents: OpenCodeBridgeAgent[] | undefined;

    const getAgents = async (): Promise<OpenCodeBridgeAgent[]> => {
      if (cachedAgents) return cachedAgents;
      try {
        // The documented success shape is the `{ location, data }` envelope.
        // `normalizeAgentList` also accepts a bare array because reading
        // `.data` off anything else throws into this catch, where the failure
        // is invisible: an empty agent list silently disables subagent gating
        // and agent-switch validation rather than reporting anything.
        cachedAgents = normalizeAgentList(await ctx.agent.list());
      } catch {
        cachedAgents = [];
      }
      return cachedAgents;
    };

    // The pinned `@opencode-ai/plugin` types predate the command-execution API
    // (PR #44765), so the context is re-viewed through a duck-typed shape. Every
    // capability behind it is probed before use.
    const v2 = ctx as unknown as V2ContextLike;

    // Native slash commands are registered before the submit_plan early return
    // below, so `workflow: "manual"`, which registers no tool, still gets them.
    // Wrapped because a transform rejection must never fail plugin setup: the
    // whole Plannotator integration would go down for a slash command that has
    // a working markdown fallback.
    try {
      await registerNativeCommands({
        ctx: v2,
        getAgents,
        getBridgeContext: () => getBridgeContext(getAgents),
      });
    } catch (error) {
      console.error(`[Plannotator] Could not register the OpenCode 2 slash commands: ${error instanceof Error ? error.message : String(error)}`);
    }

    if (shouldModifyPrompts(workflowOptions)) {
      await ctx.session.hook("context", async (event) => {
        if (
          workflowOptions.workflow === "plan-agent"
          && !isPlanningAgent(event.agent, workflowOptions)
        ) {
          delete event.tools.submit_plan;
          return;
        }

        const currentAgent = workflowOptions.workflow === "all-agents"
          ? (await getAgents()).find((candidate) => candidate.name === event.agent)
          : undefined;
        if (!allowSubagents() && currentAgent?.mode === "subagent") {
          delete event.tools.submit_plan;
          return;
        }

        if (event.tools.plan_exit) {
          event.tools.plan_exit.description =
            "Do not call this tool. Use submit_plan instead - it opens a visual review UI for plan approval.";
        }
        if (event.tools.todowrite) {
          event.tools.todowrite.description =
            "While actively planning with the user, use submit_plan instead. Only use todos once implementation begins or unless the user explicitly asks.";
        }

        replaceStrictPlanReminder(event.messages);

        const systemText = event.system.map((part) => part.text).join("\n").toLowerCase();
        if (systemText.includes("title generator") || systemText.includes("generate a title")) return;

        if (shouldInjectFullPlanningPrompt(event.agent, workflowOptions)) {
          const additions = [getPlanningPrompt()];
          const hook = readImprovementHook("enterplanmode-improve");
          const improveContext = composeImproveContext({
            pfmEnabled: loadConfig().pfmReminder === true,
            improvementHookContent: hook?.content ?? null,
          });
          if (improveContext) additions.push(improveContext);
          replacePlanningSystemParts(
            event.system,
            additions,
          );
          return;
        }

        if (!shouldInjectGenericPlanReminder(
          event.agent,
          currentAgent?.mode === "subagent",
          workflowOptions,
        )) return;

        pushComposedSystemReminder(event.system, getGenericPlanReminder());
      });
    }

    if (!shouldRegisterSubmitPlan(workflowOptions)) return;

    await ctx.tool.transform((tools) => {
      tools.add({
        name: "submit_plan",
        description:
          "Submit a plan for user review via line-range edits. First call: pass a single edit with start=1 and your full plan as content (omit end). Subsequent calls after denial: pass targeted edits using the line numbers from the previous response. The tool manages a backing file; you never touch the file directly.",
        input: {
          type: "object",
          properties: {
            edits: {
              type: "array",
              items: {
                type: "object",
                properties: {
                  start: {
                    type: "number",
                    description: "1-indexed start line (inclusive)",
                  },
                  end: {
                    type: "number",
                    description: "1-indexed end line (inclusive). Omit to replace from start through end of file.",
                  },
                  content: {
                    type: "string",
                    description: "Replacement content. Empty string deletes the line range.",
                  },
                },
                required: ["start", "content"],
                additionalProperties: false,
              },
              description: "Array of line-range edits to apply to the plan.",
            },
          },
          required: ["edits"],
          additionalProperties: false,
        },
        options: { codemode: false },
        execute: async (input, toolContext) => {
          const session = await ctx.session.get({ sessionID: toolContext.sessionID });
          const directory = session.location.directory;
          const bridge = await getBridgeContext(getAgents);
          // Same client the native command path uses, and for the same reason:
          // `sessionID` is what lets the session URL reach a remote reviewer, who
          // gets no browser opened and cannot see the plugin's console output.
          const client = createV2BridgeClient({
            ctx: v2,
            getAgents,
            sessionID: toolContext.sessionID,
          });
          const result = await executeSubmitPlan({
            edits: getPlanEdits(input),
            invokingAgent: toolContext.agent,
            sessionId: toolContext.sessionID,
            directory,
            workflowOptions,
          }, {
            reviewPlan: async ({ planContent }) => await runPlanReview({
              client,
              runtime: workflowOptions.runtime,
              planContent,
              sharingEnabled: bridge.sharingEnabled ?? true,
              shareBaseUrl: bridge.shareBaseUrl,
              pasteApiUrl: bridge.pasteApiUrl,
              timeoutSeconds: getPlanTimeoutSeconds(),
              directory,
              bridge,
            }),
            resolveTargetAgent: async ({ requestedAgent }) => await switchV2SessionAgent({
              ctx: v2,
              sessionID: toolContext.sessionID,
              requestedAgent,
              getAgents,
            }),
            // The switch above is the whole handoff on V2. Its session.prompt
            // has no `noReply` equivalent, so an injected approval note would
            // start a model turn the reviewer never asked for; the submit_plan
            // tool result already carries the approval text.
            sendApprovalHandoff: async () => {},
          });

          return { content: result };
        },
      });
    });
  },
} satisfies Plugin.Plugin;

function getPlanEdits(input: unknown): PlanEdit[] | undefined {
  if (!input || typeof input !== "object") return undefined;
  const edits = Reflect.get(input, "edits");
  return Array.isArray(edits) ? edits as PlanEdit[] : undefined;
}

function getPlanTimeoutSeconds(): number | null {
  const raw = process.env.PLANNOTATOR_PLAN_TIMEOUT_SECONDS?.trim();
  if (!raw) return DEFAULT_PLAN_TIMEOUT_SECONDS;
  const parsed = Number.parseInt(raw, 10);
  if (!Number.isFinite(parsed) || parsed < 0) {
    console.error(`[Plannotator] Invalid PLANNOTATOR_PLAN_TIMEOUT_SECONDS="${raw}". Using default ${DEFAULT_PLAN_TIMEOUT_SECONDS}s.`);
    return DEFAULT_PLAN_TIMEOUT_SECONDS;
  }
  return parsed === 0 ? null : parsed;
}

function allowSubagents(): boolean {
  const value = process.env.PLANNOTATOR_ALLOW_SUBAGENTS?.trim();
  return value === "1" || value === "true";
}

async function getBridgeContext(
  getAgents: () => Promise<OpenCodeBridgeAgent[]>,
): Promise<OpenCodeBridgeContext> {
  return {
    sharingEnabled: resolveSharingEnabled(loadConfig()),
    shareBaseUrl: process.env.PLANNOTATOR_SHARE_URL || undefined,
    pasteApiUrl: process.env.PLANNOTATOR_PASTE_URL || undefined,
    agents: await getAgents(),
  };
}

function hasEmbeddedRuntime(): boolean {
  return typeof (globalThis as typeof globalThis & { Bun?: { serve?: unknown } }).Bun?.serve === "function";
}

async function importEmbeddedRuntime(): Promise<EmbeddedRuntimeModule> {
  const builtPath = path.join(moduleDir, "embedded.js");
  if (existsSync(builtPath)) {
    return await import(pathToFileURL(builtPath).href) as EmbeddedRuntimeModule;
  }
  const sourceSpecifier = "./embedded";
  return await import(sourceSpecifier) as EmbeddedRuntimeModule;
}

function getPlanHtml(): string {
  if (planHtml) return planHtml;
  const candidates = [
    path.join(moduleDir, "plannotator.html"),
    path.join(moduleDir, "..", "plannotator.html"),
  ];
  const htmlPath = candidates.find((candidate) => existsSync(candidate));
  if (!htmlPath) throw new Error("Could not find bundled HTML asset: plannotator.html");
  planHtml = readFileSync(htmlPath, "utf-8");
  return planHtml;
}

/**
 * The embedded runtime's ready hook: put the session URL where a reviewer can
 * see it, and nowhere else.
 *
 * This still must NOT go to `client.app.log`. That is `console.error`, the same
 * stderr stream `handleServerReady` has already printed the URL to, so logging
 * here would duplicate the line in remote mode and add a stray one locally
 * (which is why this hook used to be empty). The transcript notice is a
 * different surface entirely, and on OpenCode 2 it is the only one a remote
 * reviewer can actually see: the host discards a server plugin's stderr unless
 * it was started with `OPENCODE_PRINT_LOGS=1`.
 *
 * Best-effort in both directions: an older host exposes no `session.synthetic`,
 * so `notifyUrl` is absent and this stays silent, exactly as before.
 */
export function createPlanReadyNotifier(client: V2Client): (url: string) => void {
  return (url: string) => {
    const notify = client.notifyUrl;
    if (typeof notify !== "function") return;
    try {
      void notify({ url, message: formatSessionUrlNotice(url) }).catch(() => {
        // A cosmetic notice must never surface as an unhandled rejection.
      });
    } catch {
      // Visible URL delivery is best-effort.
    }
  };
}

async function runPlanReview(input: {
  client: V2Client;
  runtime: RuntimeMode;
  planContent: string;
  sharingEnabled: boolean;
  shareBaseUrl?: string;
  pasteApiUrl?: string;
  timeoutSeconds: number | null;
  abortSignal?: AbortSignal;
  directory: string;
  bridge: OpenCodeBridgeContext;
}): Promise<OpenCodePlanReviewResult> {
  if (input.runtime === "embedded" && !hasEmbeddedRuntime()) {
    throw new Error('runtime "embedded" requires a Bun-hosted OpenCode plugin runtime. Use runtime "auto" or "cli" with this OpenCode host.');
  }

  if (input.runtime !== "cli" && hasEmbeddedRuntime()) {
    try {
      const embedded = await importEmbeddedRuntime();
      return await embedded.runEmbeddedPlanReview({
        client: input.client,
        planContent: input.planContent,
        sharingEnabled: input.sharingEnabled,
        shareBaseUrl: input.shareBaseUrl,
        pasteApiUrl: input.pasteApiUrl,
        htmlContent: getPlanHtml(),
        timeoutSeconds: input.timeoutSeconds,
        abortSignal: input.abortSignal,
        logReady: createPlanReadyNotifier(input.client),
      });
    } catch (error) {
      if (input.runtime === "embedded") throw error;
      console.error(`[Plannotator] Embedded runtime unavailable; falling back to CLI: ${error instanceof Error ? error.message : String(error)}`);
    }
  }

  return await runCliPlanReview({
    client: input.client,
    planContent: input.planContent,
    cwd: input.directory,
    timeoutSeconds: input.timeoutSeconds,
    abortSignal: input.abortSignal,
    bridge: input.bridge,
  });
}

type SystemPart = { type: "text"; text: string; [key: string]: unknown };

/**
 * Replace the system array with ONE composed text part (#1114): multiple
 * system parts corrupt Qwen3.x Jinja chat templates, which render each part
 * as its own system message. Mirrors the V1 entry (index.ts) exactly —
 * stripped existing text first, then the additions, joined by blank lines.
 *
 * Order matters: the existing texts are read and composed BEFORE the array is
 * truncated. Reordering to `system.length = 0` first silently drops the
 * host's entire system prompt (the bug class flagged in #1114's review).
 *
 * Accepted trade-off: consolidation flattens per-part metadata (e.g.
 * third-party cache hints) — template integrity beats part-level caching.
 */
export function replacePlanningSystemParts(
  system: SystemPart[],
  additions: string[],
): void {
  const stripped = stripConflictingPlanModeRules(system.map((part) => part.text));
  const composed = composeSystemPrompt([], [...stripped, ...additions.filter(Boolean)]);
  system.length = 0;
  system.push(...composed.map((text) => ({ type: "text" as const, text })));
}

/**
 * Append a reminder by composing it into a single system part (#1114) instead
 * of pushing a separate part — same Jinja-template rationale as above, and
 * the same compose-before-truncate ordering requirement.
 */
export function pushComposedSystemReminder(
  system: SystemPart[],
  reminder: string,
): void {
  const composed = composeSystemPrompt(system.map((part) => part.text), [reminder]);
  system.length = 0;
  system.push(...composed.map((text) => ({ type: "text" as const, text })));
}

function replaceStrictPlanReminder(messages: unknown[]): void {
  for (const message of messages) {
    if (!message || typeof message !== "object" || Reflect.get(message, "role") !== "user") continue;
    const content = Reflect.get(message, "content");
    if (!Array.isArray(content)) continue;
    for (const part of content) {
      if (!part || typeof part !== "object" || Reflect.get(part, "type") !== "text") continue;
      const text = Reflect.get(part, "text");
      if (typeof text !== "string" || !text.includes("STRICTLY FORBIDDEN")) continue;
      Reflect.set(part, "text", `<system-reminder>
# Plan Mode - System Reminder

CRITICAL: Plan mode ACTIVE. You are in a PLANNING phase. The ONLY file modifications
allowed are writing or editing markdown files (.md) - plans, specs, documentation, etc.
All other file edits, code modifications, and system changes are STRICTLY FORBIDDEN.
Do NOT use shell commands to manipulate non-markdown files. Commands may ONLY read/inspect.

Use submit_plan to submit the completed plan for user review. Do not proceed with
implementation until the plan is approved.
</system-reminder>`);
    }
  }
}

function getGenericPlanReminder(): string {
  return `## Plan Submission

When you have completed your plan, call the \`submit_plan\` tool to submit it for user review. Pass your full plan as a single edit: \`{ "edits": [{ "start": 1, "content": "..." }] }\`.

The user will review your plan in a visual UI where they can annotate, approve, or request changes. If rejected, the response includes your plan with line numbers; use targeted edits to revise specific sections.

Do NOT proceed with implementation until your plan is approved.`;
}

export default serverPlugin;