import { defineCommand } from "citty"
import os from "os"
import path from "path"
import { loadClaudePlugin } from "../parsers/claude"
import { targets, validateScope } from "../targets"
import type { ClaudeToOpenCodeOptions, PermissionMode } from "../converters/claude-to-opencode"
import { ensureCodexAgentsFile } from "../utils/codex-agents"
import { expandHome, resolveCodexHome, resolveTargetHome } from "../utils/resolve-home"
import { resolveOpenCodeWriteScope, resolveTargetOutputRoot } from "../utils/resolve-output"
import { detectInstalledTools } from "../utils/detect-tools"

const permissionModes: PermissionMode[] = ["none", "broad", "from-commands"]

export default defineCommand({
  meta: {
    name: "convert",
    description: "Convert a Claude Code plugin into another format",
  },
  args: {
    source: {
      type: "positional",
      required: true,
      description: "Path to the Claude plugin directory",
    },
    to: {
      type: "string",
      default: "opencode",
      description: "Target format (opencode | codex | pi | gemini | kiro | all)",
    },
    output: {
      type: "string",
      alias: "o",
      description: "Output directory (project root)",
    },
    codexHome: {
      type: "string",
      alias: "codex-home",
      description: "Write Codex output to this Codex root (default: $CODEX_HOME or ~/.codex)",
    },
    piHome: {
      type: "string",
      alias: "pi-home",
      description: "Write Pi output to this Pi root (ex: ~/.pi/agent or ./.pi)",
    },
    scope: {
      type: "string",
      description: "Scope level: global | workspace (default varies by target)",
    },
    also: {
      type: "string",
      description: "Comma-separated extra targets to generate (ex: codex)",
    },
    permissions: {
      type: "string",
      default: "broad",
      description: "Permission mapping: none | broad | from-commands",
    },
    agentMode: {
      type: "string",
      default: "subagent",
      description: "Default agent mode: primary | subagent",
    },
    inferTemperature: {
      type: "boolean",
      default: true,
      description: "Infer agent temperature from name/description",
    },
    includeSkills: {
      type: "boolean",
      default: false,
      alias: "include-skills",
      description: "For --to codex only: also emit skills and commands. Default is agents-only, the recommended pairing with `codex plugin install`. Set this flag for a legacy / standalone install without Codex native plugin install. Ignored by other targets.",
    },
  },
  async run({ args }) {
    const targetName = String(args.to)

    const permissions = String(args.permissions)
    if (!permissionModes.includes(permissions as PermissionMode)) {
      throw new Error(`Unknown permissions mode: ${permissions}`)
    }

    const plugin = await loadClaudePlugin(String(args.source))
    const outputRoot = resolveOutputRoot(args.output)
    const hasExplicitOutput = Boolean(args.output && String(args.output).trim())
    const codexHome = resolveCodexHome(args.codexHome)
    const piHome = resolveTargetHome(args.piHome, path.join(os.homedir(), ".pi", "agent"))

    const options: ClaudeToOpenCodeOptions = {
      agentMode: String(args.agentMode) === "primary" ? "primary" : "subagent",
      inferTemperature: Boolean(args.inferTemperature),
      permissions: permissions as PermissionMode,
      codexIncludeSkills: Boolean(args.includeSkills),
    }

    if (targetName === "all") {
      const detected = await detectInstalledTools()
      const activeTargets = detected.filter((t) => t.detected && targets[t.name]?.implemented)

      if (activeTargets.length === 0) {
        console.log("No installable AI coding tools detected. Use native plugin install for Claude Code, Copilot, Droid, and Qwen.")
        return
      }

      console.log(`Detected ${activeTargets.length} installable tool(s):`)
      for (const tool of detected) {
        if (tool.detected && !targets[tool.name]?.implemented) {
          console.log(`  - ${tool.name} — native plugin install; skipped`)
          continue
        }
        console.log(`  ${tool.detected ? "✓" : "✗"} ${tool.name} — ${tool.reason}`)
      }

      for (const tool of activeTargets) {
        const handler = targets[tool.name]
        if (!handler || !handler.implemented) {
          console.warn(`Skipping ${tool.name}: not implemented.`)
          continue
        }
        const bundle = handler.convert(plugin, options)
        if (!bundle) {
          console.warn(`Skipping ${tool.name}: no output returned.`)
          continue
        }
        const root = resolveTargetOutputRoot({
          targetName: tool.name,
          outputRoot,
          codexHome,
          piHome,
          pluginName: plugin.manifest.name,
          hasExplicitOutput,
        })
        const writeScope =
          tool.name === "opencode" ? resolveOpenCodeWriteScope(hasExplicitOutput, undefined) : undefined
        await handler.write(root, bundle, writeScope)
        console.log(`Converted ${plugin.manifest.name} to ${tool.name} at ${root}`)
      }

      if (activeTargets.some((t) => t.name === "codex")) {
        await ensureCodexAgentsFile(codexHome)
      }
      return
    }

    const target = targets[targetName]
    if (!target) {
      throw new Error(`Unknown target: ${targetName}`)
    }

    if (!target.implemented) {
      throw new Error(`Target ${targetName} is registered but not implemented yet.`)
    }

    const resolvedScope = validateScope(targetName, target, args.scope ? String(args.scope) : undefined)

    const primaryOutputRoot = resolveTargetOutputRoot({
      targetName,
      outputRoot,
      codexHome,
      piHome,
      pluginName: plugin.manifest.name,
      hasExplicitOutput,
      scope: resolvedScope,
    })
    const bundle = target.convert(plugin, options)
    if (!bundle) {
      throw new Error(`Target ${targetName} did not return a bundle.`)
    }

    const effectiveScope =
      targetName === "opencode" ? resolveOpenCodeWriteScope(hasExplicitOutput, resolvedScope) : resolvedScope
    await target.write(primaryOutputRoot, bundle, effectiveScope)
    console.log(`Converted ${plugin.manifest.name} to ${targetName} at ${primaryOutputRoot}`)

    const extraTargets = parseExtraTargets(args.also)
    const allTargets = [targetName, ...extraTargets]
    for (const extra of extraTargets) {
      const handler = targets[extra]
      if (!handler) {
        console.warn(`Skipping unknown target: ${extra}`)
        continue
      }
      if (!handler.implemented) {
        console.warn(`Skipping ${extra}: not implemented yet.`)
        continue
      }
      const extraBundle = handler.convert(plugin, options)
      if (!extraBundle) {
        console.warn(`Skipping ${extra}: no output returned.`)
        continue
      }
      const extraRoot = resolveTargetOutputRoot({
        targetName: extra,
        outputRoot,
        codexHome,
        piHome,
        pluginName: plugin.manifest.name,
        hasExplicitOutput,
        scope: handler.defaultScope,
      })
      const extraScope =
        extra === "opencode"
          ? resolveOpenCodeWriteScope(hasExplicitOutput, handler.defaultScope)
          : handler.defaultScope
      await handler.write(extraRoot, extraBundle, extraScope)
      console.log(`Converted ${plugin.manifest.name} to ${extra} at ${extraRoot}`)
    }

    if (allTargets.includes("codex")) {
      await ensureCodexAgentsFile(codexHome)
    }
  },
})

function parseExtraTargets(value: unknown): string[] {
  if (!value) return []
  return String(value)
    .split(",")
    .map((entry) => entry.trim())
    .filter(Boolean)
}

function resolveOutputRoot(value: unknown): string {
  if (value && String(value).trim()) {
    const expanded = expandHome(String(value).trim())
    return path.resolve(expanded)
  }
  return process.cwd()
}