import { defineStore } from 'pinia'
import { ref } from 'vue'

import { useApi } from '../composables/useApi.js'

export const useSystemActivityStore = defineStore('systemActivity', () => {
  const api = useApi()

  // Live polled state.
  const queues = ref(null)       // { queues: {name: depth|null}, fetched_at }
  const workers = ref(null)      // { workers: {hostname: {...}}, fetched_at }
  const recentRuns = ref([])   // last-60s rows (for Overview summary)
  const failures = ref(null)     // { recent, count_by_type, since }

  // Worker lanes (milestone 422): the configured slots joined to the live
  // pool. Lives here rather than in its own store because it is the same
  // domain the queues and workers above describe — a second store polling
  // /api/system/* would be two things to keep in step.
  const lanes = ref(null)        // { lanes: [...], fetched_at }

  // Paginated runs (Activity tab "All recent activity" pane).
  const runs = ref([])
  const runsCursor = ref(null)
  const runsHasMore = ref(false)
  const runsFilter = ref({ queue: null, status: null, task: null, limit: 50 })

  const loading = ref({
    queues: false, workers: false, runs: false, failures: false, lanes: false,
  })
  const lastError = ref(null)

  async function loadQueues() {
    loading.value.queues = true
    lastError.value = null
    try {
      queues.value = await api.get('/api/system/activity/queues')
    } catch (e) {
      lastError.value = e.message
    } finally {
      loading.value.queues = false
    }
  }

  async function loadWorkers() {
    loading.value.workers = true
    lastError.value = null
    try {
      workers.value = await api.get('/api/system/activity/workers')
    } catch (e) {
      lastError.value = e.message
    } finally {
      loading.value.workers = false
    }
  }

  async function loadLanes() {
    loading.value.lanes = true
    lastError.value = null
    try {
      lanes.value = await api.get('/api/system/workers')
    } catch (e) {
      lastError.value = e.message
    } finally {
      loading.value.lanes = false
    }
  }

  // Change one lane. Returns the endpoint's reply so the caller can tell a
  // stored-but-not-yet-live change (`applied: false`) from a live one — the
  // difference between "saved, the lane is restarting" and "that failed",
  // which the UI must not collapse into one message.
  //
  // Deliberately NOT swallowing the error: a refused value (400) carries the
  // sentence explaining why, and the card shows it. Returning null on failure
  // would leave the operator with a control that silently did nothing.
  async function setLane(name, fields) {
    const reply = await api.post(`/api/system/workers/${name}`, { body: fields })
    await loadLanes()
    return reply
  }

  async function loadRecentRuns() {
    // Used by the Overview summary card: pull last 60s of runs to compute
    // per-queue ok/err counts. One call covers all queues; UI groups.
    try {
      const body = await api.get('/api/system/activity/runs', {
        params: { limit: 200 },
      })
      recentRuns.value = body.runs || []
    } catch (e) {
      lastError.value = e.message
    }
  }

  async function loadRuns({ reset = false } = {}) {
    loading.value.runs = true
    lastError.value = null
    try {
      const params = { limit: runsFilter.value.limit }
      if (runsFilter.value.queue) params.queue = runsFilter.value.queue
      if (runsFilter.value.status) params.status = runsFilter.value.status
      if (runsFilter.value.task) params.task = runsFilter.value.task
      if (!reset && runsCursor.value) params.before_id = runsCursor.value
      const body = await api.get('/api/system/activity/runs', { params })
      runs.value = reset ? body.runs : [...runs.value, ...body.runs]
      runsCursor.value = body.next_cursor
      runsHasMore.value = body.next_cursor !== null
    } catch (e) {
      lastError.value = e.message
    } finally {
      loading.value.runs = false
    }
  }

  async function loadFailures() {
    loading.value.failures = true
    lastError.value = null
    try {
      failures.value = await api.get('/api/system/activity/failures')
    } catch (e) {
      lastError.value = e.message
    } finally {
      loading.value.failures = false
    }
  }

  function setFilter(filter) {
    runsFilter.value = { ...runsFilter.value, ...filter }
  }

  // One-call rollup for the always-on TopNav pipeline indicator:
  // { scheduler, queues, queued_total, running, failing }.
  const summary = ref(null)
  async function loadSummary() {
    try {
      summary.value = await api.get('/api/system/activity/summary')
    } catch (e) {
      lastError.value = e.message
    }
    return summary.value
  }

  return {
    queues, workers, recentRuns, failures, summary, lanes,
    runs, runsCursor, runsHasMore, runsFilter,
    loading, lastError,
    loadQueues, loadWorkers, loadRecentRuns, loadLanes, setLane,
    loadRuns, loadFailures, loadSummary, setFilter,
  }
})