<template>
  <AppShell>
    <NSpin :show="loading">
      <div v-if="data" class="space-y-6">
        <!-- Header -->
        <div class="flex items-center justify-between">
          <div class="flex items-center gap-3">
            <span class="text-gray-400 font-mono text-sm">#{{ data.requirement.number }}</span>
            <h1 class="text-2xl font-semibold">
              {{ data.requirement.title }}
            </h1>
            <NTag :type="data.requirement.status === 'open' ? 'success' : 'default'" size="small">
              {{ data.requirement.status === 'open' ? '开放' : '关闭' }}
            </NTag>
          </div>
          <div class="flex items-center gap-2">
            <NButton
              v-if="data.requirement.status === 'open'"
              type="warning"
              size="small"
              :loading="toggling"
              @click="onClose"
            >
              关闭需求
            </NButton>
            <NButton v-else type="primary" size="small" :loading="toggling" @click="onReopen">
              重新开放
            </NButton>
            <NButton size="small" @click="router.back()"> 返回 </NButton>
          </div>
        </div>

        <!-- Phase flow bar（阶段跳转始终由用户确认触发） -->
        <div class="flex items-center gap-1">
          <template v-for="(phase, idx) in PHASES" :key="phase">
            <NButton
              :type="phase === data.requirement.phase ? 'primary' : 'default'"
              :secondary="phase !== data.requirement.phase"
              size="small"
              :disabled="phase === data.requirement.phase"
              @click="onPhaseClick(phase)"
            >
              {{ PHASE_LABELS[phase] }}
            </NButton>
            <span v-if="idx < PHASES.length - 1" class="text-gray-300 text-xs">›</span>
          </template>
        </div>

        <!-- 左右布局：左=需求信息+当前阶段产物，右=按阶段切换的 AI 工作面板 -->
        <div class="flex gap-6 items-start">
          <div class="w-[45%] shrink-0 space-y-6">
            <!-- Description -->
            <NCard title="描述">
              <p v-if="data.requirement.description" class="text-gray-700 whitespace-pre-wrap">
                {{ data.requirement.description }}
              </p>
              <p v-else class="text-gray-400 text-sm">暂无描述</p>
            </NCard>

            <!-- 当前阶段产物（仅 AI 对话三阶段显示，保留编辑功能） -->
            <ArtifactPanel
              v-if="chatPhase"
              ref="artifactPanelRef"
              :slug="slug"
              :number="number"
              :phase="chatPhase"
              :readonly="data.requirement.status !== 'open'"
            />

            <!-- 全阶段产物与会话历史（新增） -->
            <RequirementHistoryPanel
              v-if="data"
              ref="historyPanelRef"
              :slug="slug"
              :number="number"
              :requirement-id="data.requirement.id"
              :workspace-slug="workspaceSlug"
              :current-phase="data.requirement.phase"
            />

            <!-- Workspace card -->
            <NCard title="工作区">
              <NSelect
                :value="data.requirement.workspace_id"
                :options="workspaceOptions"
                placeholder="未关联"
                clearable
                @update:value="onWorkspaceChange"
              />
            </NCard>

            <!-- Linked Issues -->
            <NCard title="关联 Issue">
              <NList v-if="data.issues.length > 0" :show-divider="false">
                <NListItem v-for="issue in data.issues" :key="issue.id">
                  <NThing>
                    <template #header>
                      <span class="font-mono text-xs text-gray-400 mr-2">#{{ issue.number }}</span>
                      <span class="text-sm font-medium">{{ issue.title }}</span>
                    </template>
                    <template #header-extra>
                      <NTag :type="issue.status === 'open' ? 'success' : 'default'" size="tiny">
                        {{ issue.status === 'open' ? '开放' : '关闭' }}
                      </NTag>
                    </template>
                  </NThing>
                </NListItem>
              </NList>
              <NEmpty v-else description="暂无关联 Issue" />
            </NCard>
          </div>

          <!-- 右栏：v-if 切换保证阶段变化时旧面板卸载（自动断流） -->
          <div class="flex-1 min-w-0">
            <RequirementChatPanel
              v-if="chatPhase"
              :slug="slug"
              :requirement="data.requirement"
              :phase="chatPhase"
              :prev-artifact="prevArtifact"
              :readonly="data.requirement.status !== 'open'"
              class="min-h-[70vh]"
              @artifact-saved="onArtifactSaved"
            />
            <RequirementAcpPanel
              v-else-if="
                data.requirement.phase === 'implementing' || data.requirement.phase === 'reviewing'
              "
              :slug="slug"
              :requirement="data.requirement"
            />
            <RequirementSummaryPanel v-else :slug="slug" :number="number" />
          </div>
        </div>
      </div>

      <div v-else-if="!loading" class="text-gray-400 text-sm py-8 text-center">
        需求不存在或无权访问。
      </div>
    </NSpin>
  </AppShell>
</template>

<script setup lang="ts">
import { ref, computed, onMounted, watch } from 'vue'
import { useRoute, useRouter } from 'vue-router'
import { useDialog } from 'naive-ui'
import { NCard, NButton, NTag, NSpin, NSelect, NList, NListItem, NThing, NEmpty } from 'naive-ui'
import AppShell from '@/layouts/AppShell.vue'
import { projectsApi } from '@/api/projects'
import { useRequirementsStore } from '@/stores/requirements'
import { useWorkspacesStore } from '@/stores/workspaces'
import { PREV_ARTIFACT_PHASE } from '@/constants/requirementPhasePrompts'
import ArtifactPanel from './components/ArtifactPanel.vue'
import RequirementChatPanel from './components/RequirementChatPanel.vue'
import RequirementAcpPanel from './components/RequirementAcpPanel.vue'
import RequirementSummaryPanel from './components/RequirementSummaryPanel.vue'
import RequirementHistoryPanel from './components/RequirementHistoryPanel.vue'
import type { Artifact, ArtifactPhase, Phase, RequirementDetail } from '@/api/projects'

const PHASES: Phase[] = ['planning', 'prototyping', 'auditing', 'implementing', 'reviewing', 'done']

const PHASE_LABELS: Record<Phase, string> = {
  planning: '规划中',
  prototyping: '原型设计',
  auditing: '评审中',
  implementing: '实施中',
  reviewing: '验收中',
  done: '已完成',
}

const CHAT_PHASES: ArtifactPhase[] = ['planning', 'prototyping', 'auditing']

const route = useRoute()
const router = useRouter()
const dialog = useDialog()
const store = useRequirementsStore()
const wsStore = useWorkspacesStore()

const slug = route.params.slug as string
const number = Number(route.params.number)

const loading = ref(false)
const toggling = ref(false)
const data = ref<RequirementDetail | null>(null)
const artifactPanelRef = ref<InstanceType<typeof ArtifactPanel> | null>(null)
const historyPanelRef = ref<InstanceType<typeof RequirementHistoryPanel> | null>(null)
const prevArtifact = ref<Artifact | null>(null)

const workspaceOptions = computed(() =>
  wsStore.list.map((w) => ({ label: `${w.name} (${w.slug})`, value: w.id })),
)

const workspaceSlug = computed(() => {
  if (!data.value?.requirement.workspace_id) return null
  return wsStore.list.find((w) => w.id === data.value!.requirement.workspace_id)?.slug ?? null
})

// 当前阶段属于 AI 对话三阶段时返回该阶段，否则 null。
const chatPhase = computed<ArtifactPhase | null>(() => {
  const p = data.value?.requirement.phase
  return p && (CHAT_PHASES as Phase[]).includes(p) ? (p as ArtifactPhase) : null
})

async function fetchData() {
  loading.value = true
  try {
    const [detail] = await Promise.all([
      projectsApi.getRequirement(slug, number),
      wsStore.fetchByProject(slug),
    ])
    data.value = detail
  } finally {
    loading.value = false
  }
}

// 上一阶段产物最新版：注入新会话 system prompt（planning 无上一阶段）。
async function loadPrevArtifact() {
  prevArtifact.value = null
  if (!chatPhase.value) return
  const prevPhase = PREV_ARTIFACT_PHASE[chatPhase.value]
  if (!prevPhase) return
  const list = await store.listArtifacts(slug, number, prevPhase)
  prevArtifact.value = list.length > 0 ? list[list.length - 1] : null
}

watch(chatPhase, loadPrevArtifact)

function onArtifactSaved() {
  artifactPanelRef.value?.refresh()
  historyPanelRef.value?.refresh()
}

async function onWorkspaceChange(v: string | null) {
  if (!data.value) return
  await projectsApi.updateRequirement(slug, number, { workspace_id: v })
  data.value.requirement.workspace_id = v
}

function onPhaseClick(target: Phase) {
  if (!data.value || data.value.requirement.phase === target) return
  const targetLabel = PHASE_LABELS[target]
  dialog.warning({
    title: '切换阶段',
    content: `确认将需求移至「${targetLabel}」阶段？`,
    positiveText: '确认',
    negativeText: '取消',
    onPositiveClick: async () => {
      const updated = await store.changePhase(slug, number, target)
      data.value!.requirement = updated
    },
  })
}

async function onClose() {
  toggling.value = true
  try {
    await store.close(slug, number)
    data.value!.requirement.status = 'closed'
  } finally {
    toggling.value = false
  }
}

async function onReopen() {
  toggling.value = true
  try {
    await store.reopen(slug, number)
    data.value!.requirement.status = 'open'
  } finally {
    toggling.value = false
  }
}

onMounted(async () => {
  await fetchData()
  await loadPrevArtifact()
})
</script>
