import z from "zod"
import * as path from "path"
import { Effect } from "effect"
import { Tool } from "./tool"
import { LSP } from "../lsp"
import { createTwoFilesPatch } from "diff"
import DESCRIPTION from "./write.txt"
import { Bus } from "../bus"
import { File } from "../file"
import { FileWatcher } from "../file/watcher"
import { Format } from "../format"
import { FileTime } from "../file/time"
import { AppFileSystem } from "../filesystem"
import { Instance } from "../project/instance"
import { trimDiff } from "./edit"
import { assertExternalDirectoryEffect } from "./external-directory"

const MAX_DIAGNOSTICS_PER_FILE = 20
const MAX_PROJECT_DIAGNOSTICS_FILES = 5

export const WriteTool = Tool.defineEffect(
  "write",
  Effect.gen(function* () {
    const lsp = yield* LSP.Service
    const fs = yield* AppFileSystem.Service
    const filetime = yield* FileTime.Service

    return {
      description: DESCRIPTION,
      parameters: z.object({
        content: z.string().describe("The content to write to the file"),
        filePath: z.string().describe("The absolute path to the file to write (must be absolute, not relative)"),
      }),
      execute: (params: { content: string; filePath: string }, ctx: Tool.Context) =>
        Effect.gen(function* () {
          const filepath = path.isAbsolute(params.filePath)
            ? params.filePath
            : path.join(Instance.directory, params.filePath)
          yield* assertExternalDirectoryEffect(ctx, filepath)

          const exists = yield* fs.existsSafe(filepath)
          const contentOld = exists ? yield* fs.readFileString(filepath) : ""
          if (exists) yield* filetime.assert(ctx.sessionID, filepath)

          const diff = trimDiff(createTwoFilesPatch(filepath, filepath, contentOld, params.content))
          yield* Effect.promise(() =>
            ctx.ask({
              permission: "edit",
              patterns: [path.relative(Instance.worktree, filepath)],
              always: ["*"],
              metadata: {
                filepath,
                diff,
              },
            }),
          )

          yield* fs.writeWithDirs(filepath, params.content)
          yield* Effect.promise(() => Format.file(filepath))
          Bus.publish(File.Event.Edited, { file: filepath })
          yield* Effect.promise(() =>
            Bus.publish(FileWatcher.Event.Updated, {
              file: filepath,
              event: exists ? "change" : "add",
            }),
          )
          yield* filetime.read(ctx.sessionID, filepath)

          let output = "Wrote file successfully."
          yield* lsp.touchFile(filepath, true)
          const diagnostics = yield* lsp.diagnostics()
          const normalizedFilepath = AppFileSystem.normalizePath(filepath)
          let projectDiagnosticsCount = 0
          for (const [file, issues] of Object.entries(diagnostics)) {
            const errors = issues.filter((item) => item.severity === 1)
            if (errors.length === 0) continue
            const limited = errors.slice(0, MAX_DIAGNOSTICS_PER_FILE)
            const suffix =
              errors.length > MAX_DIAGNOSTICS_PER_FILE
                ? `\n... and ${errors.length - MAX_DIAGNOSTICS_PER_FILE} more`
                : ""
            if (file === normalizedFilepath) {
              output += `\n\nLSP errors detected in this file, please fix:\n<diagnostics file="${filepath}">\n${limited.map(LSP.Diagnostic.pretty).join("\n")}${suffix}\n</diagnostics>`
              continue
            }
            if (projectDiagnosticsCount >= MAX_PROJECT_DIAGNOSTICS_FILES) continue
            projectDiagnosticsCount++
            output += `\n\nLSP errors detected in other files:\n<diagnostics file="${file}">\n${limited.map(LSP.Diagnostic.pretty).join("\n")}${suffix}\n</diagnostics>`
          }

          return {
            title: path.relative(Instance.worktree, filepath),
            metadata: {
              diagnostics,
              filepath,
              exists: exists,
            },
            output,
          }
        }).pipe(Effect.orDie, Effect.runPromise),
    }
  }),
)