// ingestion/internal/api/handler.go
package api

import (
	"encoding/json"
	"fmt"
	"log/slog"
	"net/http"
	"os"
	"path/filepath"
	"time"

	"github.com/mathiasbq/hyperguild/ingestion/internal/search"
)

// Handler serves the ingestion HTTP API.
type Handler struct {
	brainDir string
	logger   *slog.Logger
}

// NewHandler constructs a Handler. brainDir is the absolute path to brain/.
func NewHandler(brainDir string, logger *slog.Logger) *Handler {
	return &Handler{brainDir: brainDir, logger: logger}
}

type queryRequest struct {
	Query  string `json:"query"`
	Domain string `json:"domain,omitempty"`
	Limit  int    `json:"limit,omitempty"`
}

type writeRequest struct {
	Content  string `json:"content"`
	Filename string `json:"filename,omitempty"`
}

// Query handles POST /query — full-text search across the brain wiki.
func (h *Handler) Query(w http.ResponseWriter, r *http.Request) {
	var req queryRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "invalid JSON", http.StatusBadRequest)
		return
	}
	if req.Limit == 0 {
		req.Limit = 5
	}

	results, err := search.Query(h.brainDir, req.Query, req.Limit)
	if err != nil {
		h.logger.Error("query failed", "err", err)
		http.Error(w, "search error", http.StatusInternalServerError)
		return
	}

	writeJSON(w, map[string]any{"results": results})
}

// Write handles POST /write — write raw content to brain/raw/.
func (h *Handler) Write(w http.ResponseWriter, r *http.Request) {
	var req writeRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "invalid JSON", http.StatusBadRequest)
		return
	}
	if req.Content == "" {
		http.Error(w, "content is required", http.StatusBadRequest)
		return
	}

	filename := req.Filename
	if filename == "" {
		filename = fmt.Sprintf("%s-auto.md", time.Now().UTC().Format("2006-01-02-150405"))
	}

	rawDir := filepath.Join(h.brainDir, "raw")
	if err := os.MkdirAll(rawDir, 0o755); err != nil {
		http.Error(w, "failed to create raw dir", http.StatusInternalServerError)
		return
	}

	dest := filepath.Join(rawDir, filepath.Base(filename))
	if err := os.WriteFile(dest, []byte(req.Content), 0o644); err != nil {
		h.logger.Error("write failed", "err", err)
		http.Error(w, "write error", http.StatusInternalServerError)
		return
	}

	rel, _ := filepath.Rel(h.brainDir, dest)
	writeJSON(w, map[string]string{"path": filepath.ToSlash(rel)})
}

func writeJSON(w http.ResponseWriter, v any) {
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(v) //nolint:errcheck
}