import { create } from 'zustand'
import { useWorkspacePanelStore } from './workspacePanelStore'

export const MIN_BROWSER_ZOOM = 0.5
export const MAX_BROWSER_ZOOM = 1.5
export const DEFAULT_BROWSER_ZOOM = 1
export const BROWSER_ZOOM_STEP = 0.1

export function normalizeBrowserZoom(value: unknown): number {
  const numeric = typeof value === 'number' ? value : Number(value)
  if (!Number.isFinite(numeric)) return DEFAULT_BROWSER_ZOOM
  const clamped = Math.min(Math.max(numeric, MIN_BROWSER_ZOOM), MAX_BROWSER_ZOOM)
  return Math.round(clamped * 10) / 10
}

export type BrowserSessionState = {
  isOpen: boolean
  url: string
  title: string
  history: string[]
  historyIndex: number
  loading: boolean
  pickerActive: boolean
  canGoBack: boolean
  canGoForward: boolean
  zoom: number
}

type BrowserPanelState = {
  bySession: Record<string, BrowserSessionState>
  open: (sessionId: string, url: string) => void
  ensureBlank: (sessionId: string) => void
  navigate: (sessionId: string, url: string) => void
  goBack: (sessionId: string) => void
  goForward: (sessionId: string) => void
  setLoading: (sessionId: string, loading: boolean) => void
  setPicker: (sessionId: string, active: boolean) => void
  setZoom: (sessionId: string, zoom: number) => void
  close: (sessionId: string) => void
  setNavigated: (sessionId: string, url: string, title: string) => void
  setReady: (sessionId: string) => void
}

const empty = (url = ''): BrowserSessionState => ({
  isOpen: true,
  url,
  title: '',
  history: url ? [url] : [],
  historyIndex: url ? 0 : -1,
  loading: false,
  pickerActive: false,
  canGoBack: false,
  canGoForward: false,
  zoom: DEFAULT_BROWSER_ZOOM,
})

const withNav = (s: BrowserSessionState): BrowserSessionState => ({
  ...s,
  url: s.history[s.historyIndex] ?? s.url,
  canGoBack: s.historyIndex > 0,
  canGoForward: s.historyIndex < s.history.length - 1,
})

export const useBrowserPanelStore = create<BrowserPanelState>((set) => ({
  bySession: {},
  open: (sessionId, url) => {
    set((st) => {
      const zoom = st.bySession[sessionId]?.zoom ?? DEFAULT_BROWSER_ZOOM
      return {
        bySession: { ...st.bySession, [sessionId]: { ...empty(url), zoom, loading: true } },
      }
    })
    // The browser is one mode of the unified workbench: opening a previewable
    // link / localhost url surfaces the workbench in BROWSER mode. Import is
    // one-directional (workspacePanelStore never imports this store), so no cycle.
    const workspacePanel = useWorkspacePanelStore.getState()
    workspacePanel.openPanel(sessionId)
    workspacePanel.setMode(sessionId, 'browser')
  },
  ensureBlank: (sessionId) => set((st) => {
    const cur = st.bySession[sessionId]
    if (cur) {
      return { bySession: { ...st.bySession, [sessionId]: { ...cur, isOpen: true } } }
    }
    return { bySession: { ...st.bySession, [sessionId]: empty() } }
  }),
  navigate: (sessionId, url) => set((st) => {
    const cur = st.bySession[sessionId] ?? empty(url)
    const history = [...cur.history.slice(0, Math.max(0, cur.historyIndex + 1)), url]
    return { bySession: { ...st.bySession, [sessionId]: withNav({ ...cur, isOpen: true, loading: true, history, historyIndex: history.length - 1 }) } }
  }),
  goBack: (sessionId) => set((st) => {
    const cur = st.bySession[sessionId]; if (!cur || cur.historyIndex <= 0) return st
    return { bySession: { ...st.bySession, [sessionId]: withNav({ ...cur, historyIndex: cur.historyIndex - 1 }) } }
  }),
  goForward: (sessionId) => set((st) => {
    const cur = st.bySession[sessionId]; if (!cur || cur.historyIndex >= cur.history.length - 1) return st
    return { bySession: { ...st.bySession, [sessionId]: withNav({ ...cur, historyIndex: cur.historyIndex + 1 }) } }
  }),
  setLoading: (sessionId, loading) => set((st) => {
    const cur = st.bySession[sessionId]; if (!cur) return st
    return { bySession: { ...st.bySession, [sessionId]: { ...cur, loading } } }
  }),
  setPicker: (sessionId, active) => set((st) => {
    const cur = st.bySession[sessionId]; if (!cur) return st
    return { bySession: { ...st.bySession, [sessionId]: { ...cur, pickerActive: active } } }
  }),
  setZoom: (sessionId, zoom) => set((st) => {
    const cur = st.bySession[sessionId]; if (!cur) return st
    return { bySession: { ...st.bySession, [sessionId]: { ...cur, zoom: normalizeBrowserZoom(zoom) } } }
  }),
  close: (sessionId) => set((st) => {
    const cur = st.bySession[sessionId]; if (!cur) return st
    return { bySession: { ...st.bySession, [sessionId]: { ...cur, isOpen: false, pickerActive: false } } }
  }),
  setNavigated: (sessionId, url, title) => set((st) => {
    const cur = st.bySession[sessionId]; if (!cur) return st
    return { bySession: { ...st.bySession, [sessionId]: { ...cur, url, title, loading: false } } }
  }),
  setReady: (sessionId) => set((st) => {
    const cur = st.bySession[sessionId]; if (!cur) return st
    return { bySession: { ...st.bySession, [sessionId]: { ...cur, loading: false } } }
  }),
}))