import { Hono } from "hono"
import { stream } from "hono/streaming"
import { describeRoute, validator, resolver } from "hono-openapi"
import z from "zod"
import { Session } from "../../session"
import { MessageV2 } from "../../session/message-v2"
import { SessionPrompt } from "../../session/prompt"
import { SessionCompaction } from "../../session/compaction"
import { SessionRevert } from "../../session/revert"
import { SessionStatus } from "@/session/status"
import { SessionSummary } from "@/session/summary"
import { Todo } from "../../session/todo"
import { Agent } from "../../agent/agent"
import { Snapshot } from "@/snapshot"
import { Log } from "../../util/log"
import { PermissionNext } from "@/permission/next"
import { errors } from "../error"
import { lazy } from "../../util/lazy"

const log = Log.create({ service: "server" })

export const SessionRoutes = lazy(() =>
  new Hono()
    .get(
      "/",
      describeRoute({
        summary: "List sessions",
        description: "Get a list of all OpenCode sessions, sorted by most recently updated.",
        operationId: "session.list",
        responses: {
          200: {
            description: "List of sessions",
            content: {
              "application/json": {
                schema: resolver(Session.Info.array()),
              },
            },
          },
        },
      }),
      validator(
        "query",
        z.object({
          directory: z.string().optional().meta({ description: "Filter sessions by project directory" }),
          roots: z.coerce.boolean().optional().meta({ description: "Only return root sessions (no parentID)" }),
          start: z.coerce
            .number()
            .optional()
            .meta({ description: "Filter sessions updated on or after this timestamp (milliseconds since epoch)" }),
          search: z.string().optional().meta({ description: "Filter sessions by title (case-insensitive)" }),
          limit: z.coerce.number().optional().meta({ description: "Maximum number of sessions to return" }),
        }),
      ),
      async (c) => {
        const query = c.req.valid("query")
        const term = query.search?.toLowerCase()
        const sessions: Session.Info[] = []
        for await (const session of Session.list()) {
          if (query.directory !== undefined && session.directory !== query.directory) continue
          if (query.roots && session.parentID) continue
          if (query.start !== undefined && session.time.updated < query.start) continue
          if (term !== undefined && !session.title.toLowerCase().includes(term)) continue
          sessions.push(session)
          if (query.limit !== undefined && sessions.length >= query.limit) break
        }
        return c.json(sessions)
      },
    )
    .get(
      "/status",
      describeRoute({
        summary: "Get session status",
        description: "Retrieve the current status of all sessions, including active, idle, and completed states.",
        operationId: "session.status",
        responses: {
          200: {
            description: "Get session status",
            content: {
              "application/json": {
                schema: resolver(z.record(z.string(), SessionStatus.Info)),
              },
            },
          },
          ...errors(400),
        },
      }),
      async (c) => {
        const result = SessionStatus.list()
        return c.json(result)
      },
    )
    .get(
      "/:sessionID",
      describeRoute({
        summary: "Get session",
        description: "Retrieve detailed information about a specific OpenCode session.",
        tags: ["Session"],
        operationId: "session.get",
        responses: {
          200: {
            description: "Get session",
            content: {
              "application/json": {
                schema: resolver(Session.Info),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: Session.get.schema,
        }),
      ),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        log.info("SEARCH", { url: c.req.url })
        const session = await Session.get(sessionID)
        return c.json(session)
      },
    )
    .get(
      "/:sessionID/children",
      describeRoute({
        summary: "Get session children",
        tags: ["Session"],
        description: "Retrieve all child sessions that were forked from the specified parent session.",
        operationId: "session.children",
        responses: {
          200: {
            description: "List of children",
            content: {
              "application/json": {
                schema: resolver(Session.Info.array()),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: Session.children.schema,
        }),
      ),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        const session = await Session.children(sessionID)
        return c.json(session)
      },
    )
    .get(
      "/:sessionID/todo",
      describeRoute({
        summary: "Get session todos",
        description: "Retrieve the todo list associated with a specific session, showing tasks and action items.",
        operationId: "session.todo",
        responses: {
          200: {
            description: "Todo list",
            content: {
              "application/json": {
                schema: resolver(Todo.Info.array()),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string().meta({ description: "Session ID" }),
        }),
      ),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        const todos = await Todo.get(sessionID)
        return c.json(todos)
      },
    )
    .post(
      "/",
      describeRoute({
        summary: "Create session",
        description: "Create a new OpenCode session for interacting with AI assistants and managing conversations.",
        operationId: "session.create",
        responses: {
          ...errors(400),
          200: {
            description: "Successfully created session",
            content: {
              "application/json": {
                schema: resolver(Session.Info),
              },
            },
          },
        },
      }),
      validator("json", Session.create.schema.optional()),
      async (c) => {
        const body = c.req.valid("json") ?? {}
        const session = await Session.create(body)
        return c.json(session)
      },
    )
    .delete(
      "/:sessionID",
      describeRoute({
        summary: "Delete session",
        description: "Delete a session and permanently remove all associated data, including messages and history.",
        operationId: "session.delete",
        responses: {
          200: {
            description: "Successfully deleted session",
            content: {
              "application/json": {
                schema: resolver(z.boolean()),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: Session.remove.schema,
        }),
      ),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        await Session.remove(sessionID)
        return c.json(true)
      },
    )
    .patch(
      "/:sessionID",
      describeRoute({
        summary: "Update session",
        description: "Update properties of an existing session, such as title or other metadata.",
        operationId: "session.update",
        responses: {
          200: {
            description: "Successfully updated session",
            content: {
              "application/json": {
                schema: resolver(Session.Info),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string(),
        }),
      ),
      validator(
        "json",
        z.object({
          title: z.string().optional(),
          time: z
            .object({
              archived: z.number().optional(),
            })
            .optional(),
        }),
      ),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        const updates = c.req.valid("json")

        const updatedSession = await Session.update(sessionID, (session) => {
          if (updates.title !== undefined) {
            session.title = updates.title
          }
          if (updates.time?.archived !== undefined) session.time.archived = updates.time.archived
        })

        return c.json(updatedSession)
      },
    )
    .post(
      "/:sessionID/init",
      describeRoute({
        summary: "Initialize session",
        description:
          "Analyze the current application and create an AGENTS.md file with project-specific agent configurations.",
        operationId: "session.init",
        responses: {
          200: {
            description: "200",
            content: {
              "application/json": {
                schema: resolver(z.boolean()),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string().meta({ description: "Session ID" }),
        }),
      ),
      validator("json", Session.initialize.schema.omit({ sessionID: true })),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        const body = c.req.valid("json")
        await Session.initialize({ ...body, sessionID })
        return c.json(true)
      },
    )
    .post(
      "/:sessionID/fork",
      describeRoute({
        summary: "Fork session",
        description: "Create a new session by forking an existing session at a specific message point.",
        operationId: "session.fork",
        responses: {
          200: {
            description: "200",
            content: {
              "application/json": {
                schema: resolver(Session.Info),
              },
            },
          },
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: Session.fork.schema.shape.sessionID,
        }),
      ),
      validator("json", Session.fork.schema.omit({ sessionID: true })),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        const body = c.req.valid("json")
        const result = await Session.fork({ ...body, sessionID })
        return c.json(result)
      },
    )
    .post(
      "/:sessionID/abort",
      describeRoute({
        summary: "Abort session",
        description: "Abort an active session and stop any ongoing AI processing or command execution.",
        operationId: "session.abort",
        responses: {
          200: {
            description: "Aborted session",
            content: {
              "application/json": {
                schema: resolver(z.boolean()),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string(),
        }),
      ),
      async (c) => {
        SessionPrompt.cancel(c.req.valid("param").sessionID)
        return c.json(true)
      },
    )
    .post(
      "/:sessionID/share",
      describeRoute({
        summary: "Share session",
        description: "Create a shareable link for a session, allowing others to view the conversation.",
        operationId: "session.share",
        responses: {
          200: {
            description: "Successfully shared session",
            content: {
              "application/json": {
                schema: resolver(Session.Info),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string(),
        }),
      ),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        await Session.share(sessionID)
        const session = await Session.get(sessionID)
        return c.json(session)
      },
    )
    .get(
      "/:sessionID/diff",
      describeRoute({
        summary: "Get message diff",
        description: "Get the file changes (diff) that resulted from a specific user message in the session.",
        operationId: "session.diff",
        responses: {
          200: {
            description: "Successfully retrieved diff",
            content: {
              "application/json": {
                schema: resolver(Snapshot.FileDiff.array()),
              },
            },
          },
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: SessionSummary.diff.schema.shape.sessionID,
        }),
      ),
      validator(
        "query",
        z.object({
          messageID: SessionSummary.diff.schema.shape.messageID,
        }),
      ),
      async (c) => {
        const query = c.req.valid("query")
        const params = c.req.valid("param")
        const result = await SessionSummary.diff({
          sessionID: params.sessionID,
          messageID: query.messageID,
        })
        return c.json(result)
      },
    )
    .delete(
      "/:sessionID/share",
      describeRoute({
        summary: "Unshare session",
        description: "Remove the shareable link for a session, making it private again.",
        operationId: "session.unshare",
        responses: {
          200: {
            description: "Successfully unshared session",
            content: {
              "application/json": {
                schema: resolver(Session.Info),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: Session.unshare.schema,
        }),
      ),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        await Session.unshare(sessionID)
        const session = await Session.get(sessionID)
        return c.json(session)
      },
    )
    .post(
      "/:sessionID/summarize",
      describeRoute({
        summary: "Summarize session",
        description: "Generate a concise summary of the session using AI compaction to preserve key information.",
        operationId: "session.summarize",
        responses: {
          200: {
            description: "Summarized session",
            content: {
              "application/json": {
                schema: resolver(z.boolean()),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string().meta({ description: "Session ID" }),
        }),
      ),
      validator(
        "json",
        z.object({
          providerID: z.string(),
          modelID: z.string(),
          auto: z.boolean().optional().default(false),
        }),
      ),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        const body = c.req.valid("json")
        const session = await Session.get(sessionID)
        await SessionRevert.cleanup(session)
        const msgs = await Session.messages({ sessionID })
        let currentAgent = await Agent.defaultAgent()
        for (let i = msgs.length - 1; i >= 0; i--) {
          const info = msgs[i].info
          if (info.role === "user") {
            currentAgent = info.agent || (await Agent.defaultAgent())
            break
          }
        }
        await SessionCompaction.create({
          sessionID,
          agent: currentAgent,
          model: {
            providerID: body.providerID,
            modelID: body.modelID,
          },
          auto: body.auto,
        })
        await SessionPrompt.loop(sessionID)
        return c.json(true)
      },
    )
    .get(
      "/:sessionID/message",
      describeRoute({
        summary: "Get session messages",
        description: "Retrieve all messages in a session, including user prompts and AI responses.",
        operationId: "session.messages",
        responses: {
          200: {
            description: "List of messages",
            content: {
              "application/json": {
                schema: resolver(MessageV2.WithParts.array()),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string().meta({ description: "Session ID" }),
        }),
      ),
      validator(
        "query",
        z.object({
          limit: z.coerce.number().optional(),
        }),
      ),
      async (c) => {
        const query = c.req.valid("query")
        const messages = await Session.messages({
          sessionID: c.req.valid("param").sessionID,
          limit: query.limit,
        })
        return c.json(messages)
      },
    )
    .get(
      "/:sessionID/message/:messageID",
      describeRoute({
        summary: "Get message",
        description: "Retrieve a specific message from a session by its message ID.",
        operationId: "session.message",
        responses: {
          200: {
            description: "Message",
            content: {
              "application/json": {
                schema: resolver(
                  z.object({
                    info: MessageV2.Info,
                    parts: MessageV2.Part.array(),
                  }),
                ),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string().meta({ description: "Session ID" }),
          messageID: z.string().meta({ description: "Message ID" }),
        }),
      ),
      async (c) => {
        const params = c.req.valid("param")
        const message = await MessageV2.get({
          sessionID: params.sessionID,
          messageID: params.messageID,
        })
        return c.json(message)
      },
    )
    .delete(
      "/:sessionID/message/:messageID/part/:partID",
      describeRoute({
        description: "Delete a part from a message",
        operationId: "part.delete",
        responses: {
          200: {
            description: "Successfully deleted part",
            content: {
              "application/json": {
                schema: resolver(z.boolean()),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string().meta({ description: "Session ID" }),
          messageID: z.string().meta({ description: "Message ID" }),
          partID: z.string().meta({ description: "Part ID" }),
        }),
      ),
      async (c) => {
        const params = c.req.valid("param")
        await Session.removePart({
          sessionID: params.sessionID,
          messageID: params.messageID,
          partID: params.partID,
        })
        return c.json(true)
      },
    )
    .patch(
      "/:sessionID/message/:messageID/part/:partID",
      describeRoute({
        description: "Update a part in a message",
        operationId: "part.update",
        responses: {
          200: {
            description: "Successfully updated part",
            content: {
              "application/json": {
                schema: resolver(MessageV2.Part),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string().meta({ description: "Session ID" }),
          messageID: z.string().meta({ description: "Message ID" }),
          partID: z.string().meta({ description: "Part ID" }),
        }),
      ),
      validator("json", MessageV2.Part),
      async (c) => {
        const params = c.req.valid("param")
        const body = c.req.valid("json")
        if (body.id !== params.partID || body.messageID !== params.messageID || body.sessionID !== params.sessionID) {
          throw new Error(
            `Part mismatch: body.id='${body.id}' vs partID='${params.partID}', body.messageID='${body.messageID}' vs messageID='${params.messageID}', body.sessionID='${body.sessionID}' vs sessionID='${params.sessionID}'`,
          )
        }
        const part = await Session.updatePart(body)
        return c.json(part)
      },
    )
    .post(
      "/:sessionID/message",
      describeRoute({
        summary: "Send message",
        description: "Create and send a new message to a session, streaming the AI response.",
        operationId: "session.prompt",
        responses: {
          200: {
            description: "Created message",
            content: {
              "application/json": {
                schema: resolver(
                  z.object({
                    info: MessageV2.Assistant,
                    parts: MessageV2.Part.array(),
                  }),
                ),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string().meta({ description: "Session ID" }),
        }),
      ),
      validator("json", SessionPrompt.PromptInput.omit({ sessionID: true })),
      async (c) => {
        c.status(200)
        c.header("Content-Type", "application/json")
        return stream(c, async (stream) => {
          const sessionID = c.req.valid("param").sessionID
          const body = c.req.valid("json")
          const msg = await SessionPrompt.prompt({ ...body, sessionID })
          stream.write(JSON.stringify(msg))
        })
      },
    )
    .post(
      "/:sessionID/prompt_async",
      describeRoute({
        summary: "Send async message",
        description:
          "Create and send a new message to a session asynchronously, starting the session if needed and returning immediately.",
        operationId: "session.prompt_async",
        responses: {
          204: {
            description: "Prompt accepted",
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string().meta({ description: "Session ID" }),
        }),
      ),
      validator("json", SessionPrompt.PromptInput.omit({ sessionID: true })),
      async (c) => {
        c.status(204)
        c.header("Content-Type", "application/json")
        return stream(c, async () => {
          const sessionID = c.req.valid("param").sessionID
          const body = c.req.valid("json")
          SessionPrompt.prompt({ ...body, sessionID })
        })
      },
    )
    .post(
      "/:sessionID/command",
      describeRoute({
        summary: "Send command",
        description: "Send a new command to a session for execution by the AI assistant.",
        operationId: "session.command",
        responses: {
          200: {
            description: "Created message",
            content: {
              "application/json": {
                schema: resolver(
                  z.object({
                    info: MessageV2.Assistant,
                    parts: MessageV2.Part.array(),
                  }),
                ),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string().meta({ description: "Session ID" }),
        }),
      ),
      validator("json", SessionPrompt.CommandInput.omit({ sessionID: true })),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        const body = c.req.valid("json")
        const msg = await SessionPrompt.command({ ...body, sessionID })
        return c.json(msg)
      },
    )
    .post(
      "/:sessionID/shell",
      describeRoute({
        summary: "Run shell command",
        description: "Execute a shell command within the session context and return the AI's response.",
        operationId: "session.shell",
        responses: {
          200: {
            description: "Created message",
            content: {
              "application/json": {
                schema: resolver(MessageV2.Assistant),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string().meta({ description: "Session ID" }),
        }),
      ),
      validator("json", SessionPrompt.ShellInput.omit({ sessionID: true })),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        const body = c.req.valid("json")
        const msg = await SessionPrompt.shell({ ...body, sessionID })
        return c.json(msg)
      },
    )
    .post(
      "/:sessionID/revert",
      describeRoute({
        summary: "Revert message",
        description: "Revert a specific message in a session, undoing its effects and restoring the previous state.",
        operationId: "session.revert",
        responses: {
          200: {
            description: "Updated session",
            content: {
              "application/json": {
                schema: resolver(Session.Info),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string(),
        }),
      ),
      validator("json", SessionRevert.RevertInput.omit({ sessionID: true })),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        log.info("revert", c.req.valid("json"))
        const session = await SessionRevert.revert({
          sessionID,
          ...c.req.valid("json"),
        })
        return c.json(session)
      },
    )
    .post(
      "/:sessionID/unrevert",
      describeRoute({
        summary: "Restore reverted messages",
        description: "Restore all previously reverted messages in a session.",
        operationId: "session.unrevert",
        responses: {
          200: {
            description: "Updated session",
            content: {
              "application/json": {
                schema: resolver(Session.Info),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string(),
        }),
      ),
      async (c) => {
        const sessionID = c.req.valid("param").sessionID
        const session = await SessionRevert.unrevert({ sessionID })
        return c.json(session)
      },
    )
    .post(
      "/:sessionID/permissions/:permissionID",
      describeRoute({
        summary: "Respond to permission",
        deprecated: true,
        description: "Approve or deny a permission request from the AI assistant.",
        operationId: "permission.respond",
        responses: {
          200: {
            description: "Permission processed successfully",
            content: {
              "application/json": {
                schema: resolver(z.boolean()),
              },
            },
          },
          ...errors(400, 404),
        },
      }),
      validator(
        "param",
        z.object({
          sessionID: z.string(),
          permissionID: z.string(),
        }),
      ),
      validator("json", z.object({ response: PermissionNext.Reply })),
      async (c) => {
        const params = c.req.valid("param")
        PermissionNext.reply({
          requestID: params.permissionID,
          reply: c.req.valid("json").response,
        })
        return c.json(true)
      },
    ),
)
