package web

import (
	"net/http"
	"os"
	"path/filepath"
	"strings"

	"keel/internal/settings"

	"github.com/gin-gonic/gin"
)

// SetSettings injects the persisted settings, their file path, and the applier
// closure (built by main, which owns adapter construction). Mirrors the
// controller's Set* injection so web never imports ai/tasks/knowledge.
func (s *Server) SetSettings(path string, current settings.Settings, apply func(settings.Settings) error) {
	s.settingsMu.Lock()
	s.settingsPath = path
	s.settings = current
	s.applyFn = apply
	s.settingsMu.Unlock()
}

func (s *Server) handleGetSettings(c *gin.Context) {
	s.settingsMu.Lock()
	cur := s.settings
	s.settingsMu.Unlock()
	c.JSON(http.StatusOK, cur)
}

// handlePostSettings applies the new settings first, then persists them. The
// applier checks the backend before mutating any state, so an invalid backend
// yields 400 with nothing saved and the prior wiring intact. If Save fails after
// a successful apply, the running adapters are already rewired but the file and
// the in-memory copy are left unchanged; that surfaces as 500.
func (s *Server) handlePostSettings(c *gin.Context) {
	var req settings.Settings
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid json"})
		return
	}
	s.applyMu.Lock()
	defer s.applyMu.Unlock()
	s.settingsMu.Lock()
	apply := s.applyFn
	path := s.settingsPath
	// aw_url is not exposed in the settings form; preserve the persisted value
	// so a UI save never blanks a configured AW URL.
	if req.AWURL == "" {
		req.AWURL = s.settings.AWURL
	}
	// Likewise preserve ambient fields when a caller omits them, so a partial
	// POST never clobbers a configured ambient dial.
	if req.AmbientMode == "" {
		req.AmbientMode = s.settings.AmbientMode
	}
	if req.AmbientCadenceSecs <= 0 {
		req.AmbientCadenceSecs = s.settings.AmbientCadenceSecs
	}
	s.settingsMu.Unlock()
	if apply == nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "settings not wired"})
		return
	}
	if err := apply(req); err != nil {
		// Apply validates the backend before mutating anything, so any error
		// (invalid backend or otherwise) means nothing changed; surface it as 400.
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	if err := settings.Save(path, req); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}
	s.settingsMu.Lock()
	s.settings = req
	s.settingsMu.Unlock()
	s.broadcast()
	c.JSON(http.StatusOK, req)
}

type browseEntry struct {
	Name  string `json:"name"`
	Path  string `json:"path"`
	IsDir bool   `json:"is_dir"`
}

type browseResponse struct {
	Dir     string        `json:"dir"`
	Parent  string        `json:"parent"`
	Entries []browseEntry `json:"entries"`
}

// handleBrowse lists subdirectories plus .md files under dir, so the UI can build
// a file picker that returns a real server-side path. Dotfiles are NOT hidden —
// the default profile lives under ~/.keel. Localhost-only daemon; no jail
// beyond OS permissions (same trust boundary as the rest of the UI).
func (s *Server) handleBrowse(c *gin.Context) {
	dir := strings.TrimSpace(c.Query("dir"))
	if dir == "" {
		dir = s.browseStart()
	}
	dir = filepath.Clean(dir)
	infos, err := os.ReadDir(dir)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	resp := browseResponse{Dir: dir, Parent: filepath.Dir(dir), Entries: []browseEntry{}}
	for _, e := range infos {
		name := e.Name()
		full := filepath.Join(dir, name)
		if e.IsDir() {
			resp.Entries = append(resp.Entries, browseEntry{Name: name, Path: full, IsDir: true})
		} else if strings.HasSuffix(name, ".md") {
			resp.Entries = append(resp.Entries, browseEntry{Name: name, Path: full})
		}
	}
	c.JSON(http.StatusOK, resp)
}

// browseStart picks the directory of the current knowledge path, else $HOME.
func (s *Server) browseStart() string {
	s.settingsMu.Lock()
	kp := s.settings.KnowledgePath
	s.settingsMu.Unlock()
	if kp != "" {
		return filepath.Dir(kp)
	}
	if home, err := os.UserHomeDir(); err == nil {
		return home
	}
	return "/"
}