import { tool } from '@strands-agents/sdk'
import { z } from 'zod'

// ────────────────────────────────────────────────────────────────────
// use_github — GraphQL-first GitHub tool (mirrors devduck's use_github)
// ────────────────────────────────────────────────────────────────────
// One tool, any GraphQL query or mutation. REST helpers below are thin
// wrappers that build GraphQL under the hood so there's exactly one
// auth + transport path to maintain.

function getToken(): string | null {
  try {
    const raw = localStorage.getItem('careless-v2-settings')
    return raw ? JSON.parse(raw).githubToken : null
  } catch {
    return null
  }
}

interface GraphQLResult {
  status: 'success' | 'error'
  data?: unknown
  errors?: unknown
  rate_limit?: { remaining: number; limit: number; reset_at?: string }
  message?: string
}

async function graphql(
  query: string,
  variables?: Record<string, unknown>,
): Promise<GraphQLResult> {
  const token = getToken()
  if (!token) {
    return {
      status: 'error',
      message:
        'GITHUB_TOKEN missing. Set githubToken in Settings (Settings > Credentials).',
    }
  }

  try {
    const res = await fetch('https://api.github.com/graphql', {
      method: 'POST',
      headers: {
        Authorization: `Bearer ${token}`,
        'Content-Type': 'application/json',
        Accept: 'application/vnd.github+json',
      },
      body: JSON.stringify({ query, variables: variables || {} }),
    })

    const rateRemaining = res.headers.get('x-ratelimit-remaining')
    const rateLimit = res.headers.get('x-ratelimit-limit')
    const rateReset = res.headers.get('x-ratelimit-reset')
    const rate_limit = rateRemaining
      ? {
          remaining: Number(rateRemaining),
          limit: Number(rateLimit || 0),
          reset_at: rateReset
            ? new Date(Number(rateReset) * 1000).toISOString()
            : undefined,
        }
      : undefined

    if (!res.ok) {
      const text = await res.text().catch(() => '')
      return {
        status: 'error',
        message: `HTTP ${res.status}: ${text.slice(0, 500)}`,
        rate_limit,
      }
    }

    const body = await res.json()
    if (body.errors) {
      return { status: 'error', errors: body.errors, rate_limit }
    }
    return { status: 'success', data: body.data, rate_limit }
  } catch (err: unknown) {
    return { status: 'error', message: (err as Error).message }
  }
}

// Validate query_type hint vs. the query text (lightweight — GitHub's
// GraphQL server is authoritative).
function validateQueryType(
  queryType: 'query' | 'mutation',
  query: string,
): string | null {
  const trimmed = query.trim().toLowerCase()
  if (queryType === 'mutation' && !trimmed.startsWith('mutation')) {
    return "query_type='mutation' but query does not start with 'mutation'"
  }
  if (
    queryType === 'query' &&
    trimmed.startsWith('mutation')
  ) {
    return "query_type='query' but query starts with 'mutation'"
  }
  return null
}

// ────────────────────────────────────────────────────────────────────
// The universal tool
// ────────────────────────────────────────────────────────────────────

export const useGithubTool = tool({
  name: 'use_github',
  description:
    'Execute any GitHub GraphQL query or mutation. Supports the full v4 schema: ' +
    'repositories, issues, PRs, users, orgs, projects, commits, branches, security. ' +
    'Requires githubToken in Settings. Returns data + rate limit info.',
  inputSchema: z.object({
    query_type: z
      .enum(['query', 'mutation'])
      .describe('Type of GraphQL operation'),
    query: z.string().describe('The GraphQL query or mutation string'),
    variables: z
      .record(z.string(), z.any())
      .optional()
      .describe('Optional variables for the query'),
    label: z
      .string()
      .optional()
      .describe('Human-readable description of the operation (for logs)'),
  }),
  callback: async ({ query_type, query, variables, label }) => {
    const validationError = validateQueryType(query_type, query)
    if (validationError) {
      return JSON.stringify({ status: 'error', message: validationError })
    }

    if (label) {
      // eslint-disable-next-line no-console
      console.log(`[use_github] ${query_type}: ${label}`)
    }

    const result = await graphql(query, variables)
    return JSON.stringify(result)
  },
})

// ────────────────────────────────────────────────────────────────────
// Thin convenience wrappers (backward compat with existing callers)
// All three build GraphQL under the hood — one auth path, one transport.
// ────────────────────────────────────────────────────────────────────

export const githubSearchRepoTool = tool({
  name: 'github_search_repos',
  description:
    'Search GitHub repositories (convenience wrapper on use_github).',
  inputSchema: z.object({
    query: z.string(),
    limit: z.number().optional(),
  }),
  callback: async ({ query, limit }) => {
    const gql = `
      query($q: String!, $first: Int!) {
        search(query: $q, type: REPOSITORY, first: $first) {
          repositoryCount
          nodes {
            ... on Repository {
              nameWithOwner
              description
              stargazerCount
              forkCount
              primaryLanguage { name }
              url
              updatedAt
            }
          }
        }
      }`
    const result = await graphql(gql, { q: query, first: limit || 5 })
    if (result.status !== 'success') return JSON.stringify(result)

    type SearchNode = {
      nameWithOwner: string
      description: string | null
      stargazerCount: number
      forkCount: number
      primaryLanguage: { name: string } | null
      url: string
      updatedAt: string
    }
    const search = (result.data as { search?: { repositoryCount: number; nodes: SearchNode[] } })
      ?.search
    const results =
      search?.nodes.map((r) => ({
        name: r.nameWithOwner,
        description: r.description,
        stars: r.stargazerCount,
        forks: r.forkCount,
        language: r.primaryLanguage?.name,
        url: r.url,
        updated_at: r.updatedAt,
      })) || []
    return JSON.stringify({
      status: 'success',
      total: search?.repositoryCount || 0,
      results,
      rate_limit: result.rate_limit,
    })
  },
})

export const githubGetRepoTool = tool({
  name: 'github_get_repo',
  description:
    'Get GitHub repo info (convenience wrapper on use_github). Includes open issue + PR counts.',
  inputSchema: z.object({ owner: z.string(), name: z.string() }),
  callback: async ({ owner, name }) => {
    const gql = `
      query($owner: String!, $name: String!) {
        repository(owner: $owner, name: $name) {
          nameWithOwner
          description
          stargazerCount
          forkCount
          primaryLanguage { name }
          url
          updatedAt
          pushedAt
          isArchived
          isFork
          defaultBranchRef { name }
          issues(states: OPEN) { totalCount }
          pullRequests(states: OPEN) { totalCount }
          licenseInfo { spdxId }
          diskUsage
        }
      }`
    const result = await graphql(gql, { owner, name })
    if (result.status !== 'success') return JSON.stringify(result)

    type Repo = {
      nameWithOwner: string
      description: string | null
      stargazerCount: number
      forkCount: number
      primaryLanguage: { name: string } | null
      url: string
      updatedAt: string
      pushedAt: string
      isArchived: boolean
      isFork: boolean
      defaultBranchRef: { name: string } | null
      issues: { totalCount: number }
      pullRequests: { totalCount: number }
      licenseInfo: { spdxId: string } | null
      diskUsage: number
    }
    const r = (result.data as { repository: Repo | null })?.repository
    if (!r) {
      return JSON.stringify({
        status: 'error',
        message: `Repo not found: ${owner}/${name}`,
      })
    }
    return JSON.stringify({
      status: 'success',
      name: r.nameWithOwner,
      description: r.description,
      stars: r.stargazerCount,
      forks: r.forkCount,
      language: r.primaryLanguage?.name,
      url: r.url,
      updated_at: r.updatedAt,
      pushed_at: r.pushedAt,
      archived: r.isArchived,
      fork: r.isFork,
      default_branch: r.defaultBranchRef?.name,
      open_issues: r.issues.totalCount,
      open_prs: r.pullRequests.totalCount,
      license: r.licenseInfo?.spdxId,
      disk_usage_kb: r.diskUsage,
      rate_limit: result.rate_limit,
    })
  },
})

export const githubGetFileTool = tool({
  name: 'github_get_file',
  description:
    'Fetch a file from a GitHub repo, decoded. Uses GraphQL object/blob expression.',
  inputSchema: z.object({
    owner: z.string(),
    name: z.string(),
    path: z.string(),
    branch: z.string().optional(),
  }),
  callback: async ({ owner, name, path, branch }) => {
    // expression: "<ref>:<path>" — ref defaults to HEAD when omitted
    const expression = `${branch || 'HEAD'}:${path}`
    const gql = `
      query($owner: String!, $name: String!, $expr: String!) {
        repository(owner: $owner, name: $name) {
          object(expression: $expr) {
            ... on Blob {
              text
              byteSize
              isBinary
              oid
            }
          }
        }
      }`
    const result = await graphql(gql, { owner, name, expr: expression })
    if (result.status !== 'success') return JSON.stringify(result)

    type Blob = {
      text: string | null
      byteSize: number
      isBinary: boolean
      oid: string
    }
    const obj = (
      result.data as { repository: { object: Blob | null } | null }
    )?.repository?.object
    if (!obj) {
      return JSON.stringify({
        status: 'error',
        message: `File not found: ${owner}/${name}:${expression}`,
      })
    }
    if (obj.isBinary) {
      return JSON.stringify({
        status: 'error',
        message: `Binary file (${obj.byteSize} bytes) — GraphQL can't return bytes. Use raw.githubusercontent.com instead.`,
        oid: obj.oid,
      })
    }
    return JSON.stringify({
      status: 'success',
      path,
      size: obj.byteSize,
      oid: obj.oid,
      content: (obj.text || '').slice(0, 20000),
      rate_limit: result.rate_limit,
    })
  },
})

export const GITHUB_TOOLS = [
  useGithubTool,
  githubSearchRepoTool,
  githubGetRepoTool,
  githubGetFileTool,
]