import { NodeChildProcessSpawner, NodeFileSystem, NodePath } from "@effect/platform-node"
import { Effect, Layer, Schema, ServiceMap, Stream } from "effect"
import { FetchHttpClient, HttpClient, HttpClientRequest, HttpClientResponse } from "effect/unstable/http"
import { withTransientReadRetry } from "@/util/effect-http-client"
import { ChildProcess, ChildProcessSpawner } from "effect/unstable/process"
import path from "path"
import z from "zod"
import { BusEvent } from "@/bus/bus-event"
import { Flag } from "../flag/flag"
import { Log } from "../util/log"

declare global {
  const OPENCODE_VERSION: string
  const OPENCODE_CHANNEL: string
}

export namespace Installation {
  const log = Log.create({ service: "installation" })

  export type Method = "curl" | "npm" | "yarn" | "pnpm" | "bun" | "brew" | "scoop" | "choco" | "unknown"

  export const Event = {
    Updated: BusEvent.define(
      "installation.updated",
      z.object({
        version: z.string(),
      }),
    ),
    UpdateAvailable: BusEvent.define(
      "installation.update-available",
      z.object({
        version: z.string(),
      }),
    ),
  }

  export const Info = z
    .object({
      version: z.string(),
      latest: z.string(),
    })
    .meta({
      ref: "InstallationInfo",
    })
  export type Info = z.infer<typeof Info>

  export const VERSION = typeof OPENCODE_VERSION === "string" ? OPENCODE_VERSION : "local"
  export const CHANNEL = typeof OPENCODE_CHANNEL === "string" ? OPENCODE_CHANNEL : "local"
  export const USER_AGENT = `opencode/${CHANNEL}/${VERSION}/${Flag.OPENCODE_CLIENT}`

  export function isPreview() {
    return CHANNEL !== "latest"
  }

  export function isLocal() {
    return CHANNEL === "local"
  }

  export class UpgradeFailedError extends Schema.TaggedErrorClass<UpgradeFailedError>()("UpgradeFailedError", {
    stderr: Schema.String,
  }) {}

  // Response schemas for external version APIs
  const GitHubRelease = Schema.Struct({ tag_name: Schema.String })
  const NpmPackage = Schema.Struct({ version: Schema.String })
  const BrewFormula = Schema.Struct({ versions: Schema.Struct({ stable: Schema.String }) })
  const BrewInfoV2 = Schema.Struct({
    formulae: Schema.Array(Schema.Struct({ versions: Schema.Struct({ stable: Schema.String }) })),
  })
  const ChocoPackage = Schema.Struct({
    d: Schema.Struct({ results: Schema.Array(Schema.Struct({ Version: Schema.String })) }),
  })
  const ScoopManifest = NpmPackage

  export interface Interface {
    readonly info: () => Effect.Effect<Info>
    readonly method: () => Effect.Effect<Method>
    readonly latest: (method?: Method) => Effect.Effect<string>
    readonly upgrade: (method: Method, target: string) => Effect.Effect<void, UpgradeFailedError>
  }

  export class Service extends ServiceMap.Service<Service, Interface>()("@opencode/Installation") {}

  export const layer: Layer.Layer<
    Service,
    never,
    HttpClient.HttpClient | ChildProcessSpawner.ChildProcessSpawner
  > = Layer.effect(
    Service,
    Effect.gen(function* () {
      const http = yield* HttpClient.HttpClient
      const httpOk = HttpClient.filterStatusOk(withTransientReadRetry(http))
      const spawner = yield* ChildProcessSpawner.ChildProcessSpawner

      const text = Effect.fnUntraced(
        function* (cmd: string[], opts?: { cwd?: string; env?: Record<string, string> }) {
          const proc = ChildProcess.make(cmd[0], cmd.slice(1), {
            cwd: opts?.cwd,
            env: opts?.env,
            extendEnv: true,
          })
          const handle = yield* spawner.spawn(proc)
          const out = yield* Stream.mkString(Stream.decodeText(handle.stdout))
          yield* handle.exitCode
          return out
        },
        Effect.scoped,
        Effect.catch(() => Effect.succeed("")),
      )

      const run = Effect.fnUntraced(
        function* (cmd: string[], opts?: { cwd?: string; env?: Record<string, string> }) {
          const proc = ChildProcess.make(cmd[0], cmd.slice(1), {
            cwd: opts?.cwd,
            env: opts?.env,
            extendEnv: true,
          })
          const handle = yield* spawner.spawn(proc)
          const [stdout, stderr] = yield* Effect.all(
            [Stream.mkString(Stream.decodeText(handle.stdout)), Stream.mkString(Stream.decodeText(handle.stderr))],
            { concurrency: 2 },
          )
          const code = yield* handle.exitCode
          return { code, stdout, stderr }
        },
        Effect.scoped,
        Effect.catch(() => Effect.succeed({ code: ChildProcessSpawner.ExitCode(1), stdout: "", stderr: "" })),
      )

      const getBrewFormula = Effect.fnUntraced(function* () {
        const tapFormula = yield* text(["brew", "list", "--formula", "anomalyco/tap/opencode"])
        if (tapFormula.includes("opencode")) return "anomalyco/tap/opencode"
        const coreFormula = yield* text(["brew", "list", "--formula", "opencode"])
        if (coreFormula.includes("opencode")) return "opencode"
        return "opencode"
      })

      const upgradeCurl = Effect.fnUntraced(
        function* (target: string) {
          const response = yield* httpOk.execute(HttpClientRequest.get("https://opencode.ai/install"))
          const body = yield* response.text
          const bodyBytes = new TextEncoder().encode(body)
          const proc = ChildProcess.make("bash", [], {
            stdin: Stream.make(bodyBytes),
            env: { VERSION: target },
            extendEnv: true,
          })
          const handle = yield* spawner.spawn(proc)
          const [stdout, stderr] = yield* Effect.all(
            [Stream.mkString(Stream.decodeText(handle.stdout)), Stream.mkString(Stream.decodeText(handle.stderr))],
            { concurrency: 2 },
          )
          const code = yield* handle.exitCode
          return { code, stdout, stderr }
        },
        Effect.scoped,
        Effect.orDie,
      )

      const methodImpl = Effect.fn("Installation.method")(function* () {
        if (process.execPath.includes(path.join(".opencode", "bin"))) return "curl" as Method
        if (process.execPath.includes(path.join(".local", "bin"))) return "curl" as Method
        const exec = process.execPath.toLowerCase()

        const checks: Array<{ name: Method; command: () => Effect.Effect<string> }> = [
          { name: "npm", command: () => text(["npm", "list", "-g", "--depth=0"]) },
          { name: "yarn", command: () => text(["yarn", "global", "list"]) },
          { name: "pnpm", command: () => text(["pnpm", "list", "-g", "--depth=0"]) },
          { name: "bun", command: () => text(["bun", "pm", "ls", "-g"]) },
          { name: "brew", command: () => text(["brew", "list", "--formula", "opencode"]) },
          { name: "scoop", command: () => text(["scoop", "list", "opencode"]) },
          { name: "choco", command: () => text(["choco", "list", "--limit-output", "opencode"]) },
        ]

        checks.sort((a, b) => {
          const aMatches = exec.includes(a.name)
          const bMatches = exec.includes(b.name)
          if (aMatches && !bMatches) return -1
          if (!aMatches && bMatches) return 1
          return 0
        })

        for (const check of checks) {
          const output = yield* check.command()
          const installedName =
            check.name === "brew" || check.name === "choco" || check.name === "scoop" ? "opencode" : "opencode-ai"
          if (output.includes(installedName)) {
            return check.name
          }
        }

        return "unknown" as Method
      })

      const latestImpl = Effect.fn("Installation.latest")(
        function* (installMethod?: Method) {
          const detectedMethod = installMethod || (yield* methodImpl())

          if (detectedMethod === "brew") {
            const formula = yield* getBrewFormula()
            if (formula.includes("/")) {
              const infoJson = yield* text(["brew", "info", "--json=v2", formula])
              const info = yield* Schema.decodeUnknownEffect(Schema.fromJsonString(BrewInfoV2))(infoJson)
              return info.formulae[0].versions.stable
            }
            const response = yield* httpOk.execute(
              HttpClientRequest.get("https://formulae.brew.sh/api/formula/opencode.json").pipe(
                HttpClientRequest.acceptJson,
              ),
            )
            const data = yield* HttpClientResponse.schemaBodyJson(BrewFormula)(response)
            return data.versions.stable
          }

          if (detectedMethod === "npm" || detectedMethod === "bun" || detectedMethod === "pnpm") {
            const r = (yield* text(["npm", "config", "get", "registry"])).trim()
            const reg = r || "https://registry.npmjs.org"
            const registry = reg.endsWith("/") ? reg.slice(0, -1) : reg
            const channel = CHANNEL
            const response = yield* httpOk.execute(
              HttpClientRequest.get(`${registry}/opencode-ai/${channel}`).pipe(HttpClientRequest.acceptJson),
            )
            const data = yield* HttpClientResponse.schemaBodyJson(NpmPackage)(response)
            return data.version
          }

          if (detectedMethod === "choco") {
            const response = yield* httpOk.execute(
              HttpClientRequest.get(
                "https://community.chocolatey.org/api/v2/Packages?$filter=Id%20eq%20%27opencode%27%20and%20IsLatestVersion&$select=Version",
              ).pipe(HttpClientRequest.setHeaders({ Accept: "application/json;odata=verbose" })),
            )
            const data = yield* HttpClientResponse.schemaBodyJson(ChocoPackage)(response)
            return data.d.results[0].Version
          }

          if (detectedMethod === "scoop") {
            const response = yield* httpOk.execute(
              HttpClientRequest.get(
                "https://raw.githubusercontent.com/ScoopInstaller/Main/master/bucket/opencode.json",
              ).pipe(HttpClientRequest.setHeaders({ Accept: "application/json" })),
            )
            const data = yield* HttpClientResponse.schemaBodyJson(ScoopManifest)(response)
            return data.version
          }

          const response = yield* httpOk.execute(
            HttpClientRequest.get("https://api.github.com/repos/anomalyco/opencode/releases/latest").pipe(
              HttpClientRequest.acceptJson,
            ),
          )
          const data = yield* HttpClientResponse.schemaBodyJson(GitHubRelease)(response)
          return data.tag_name.replace(/^v/, "")
        },
        Effect.orDie,
      )

      const upgradeImpl = Effect.fn("Installation.upgrade")(function* (m: Method, target: string) {
        let result: { code: ChildProcessSpawner.ExitCode; stdout: string; stderr: string } | undefined
        switch (m) {
          case "curl":
            result = yield* upgradeCurl(target)
            break
          case "npm":
            result = yield* run(["npm", "install", "-g", `opencode-ai@${target}`])
            break
          case "pnpm":
            result = yield* run(["pnpm", "install", "-g", `opencode-ai@${target}`])
            break
          case "bun":
            result = yield* run(["bun", "install", "-g", `opencode-ai@${target}`])
            break
          case "brew": {
            const formula = yield* getBrewFormula()
            const env = { HOMEBREW_NO_AUTO_UPDATE: "1" }
            if (formula.includes("/")) {
              const tap = yield* run(["brew", "tap", "anomalyco/tap"], { env })
              if (tap.code !== 0) {
                result = tap
                break
              }
              const repo = yield* text(["brew", "--repo", "anomalyco/tap"])
              const dir = repo.trim()
              if (dir) {
                const pull = yield* run(["git", "pull", "--ff-only"], { cwd: dir, env })
                if (pull.code !== 0) {
                  result = pull
                  break
                }
              }
            }
            result = yield* run(["brew", "upgrade", formula], { env })
            break
          }
          case "choco":
            result = yield* run(["choco", "upgrade", "opencode", `--version=${target}`, "-y"])
            break
          case "scoop":
            result = yield* run(["scoop", "install", `opencode@${target}`])
            break
          default:
            throw new Error(`Unknown method: ${m}`)
        }
        if (!result || result.code !== 0) {
          const stderr = m === "choco" ? "not running from an elevated command shell" : result?.stderr || ""
          return yield* new UpgradeFailedError({ stderr })
        }
        log.info("upgraded", {
          method: m,
          target,
          stdout: result.stdout,
          stderr: result.stderr,
        })
        yield* text([process.execPath, "--version"])
      })

      return Service.of({
        info: Effect.fn("Installation.info")(function* () {
          return {
            version: VERSION,
            latest: yield* latestImpl(),
          }
        }),
        method: methodImpl,
        latest: latestImpl,
        upgrade: upgradeImpl,
      })
    }),
  )

  export const defaultLayer = layer.pipe(
    Layer.provide(FetchHttpClient.layer),
    Layer.provide(NodeChildProcessSpawner.layer),
    Layer.provide(NodeFileSystem.layer),
    Layer.provide(NodePath.layer),
  )

  // Legacy adapters — dynamic import avoids circular dependency since
  // foundational modules (db.ts, provider/models.ts) import Installation
  // at load time, and runtime transitively loads those same modules.
  async function runPromise<A>(f: (service: Interface) => Effect.Effect<A, any>) {
    const { runtime } = await import("@/effect/runtime")
    return runtime.runPromise(Service.use(f))
  }

  export function info(): Promise<Info> {
    return runPromise((svc) => svc.info())
  }

  export function method(): Promise<Method> {
    return runPromise((svc) => svc.method())
  }

  export function latest(installMethod?: Method): Promise<string> {
    return runPromise((svc) => svc.latest(installMethod))
  }

  export function upgrade(m: Method, target: string): Promise<void> {
    return runPromise((svc) => svc.upgrade(m, target))
  }
}