package api

import (
	"encoding/json"
	"errors"
	"net/http"
	"time"

	"github.com/google/uuid"
	"github.com/thepeterstone/claudomator/internal/storage"
	"github.com/thepeterstone/claudomator/internal/task"
)

func (s *Server) handleListTemplates(w http.ResponseWriter, r *http.Request) {
	templates, err := s.store.ListTemplates()
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}
	if templates == nil {
		templates = []*storage.Template{}
	}
	writeJSON(w, http.StatusOK, templates)
}

func (s *Server) handleCreateTemplate(w http.ResponseWriter, r *http.Request) {
	var input struct {
		Name        string            `json:"name"`
		Description string            `json:"description"`
		Claude      task.ClaudeConfig `json:"claude"`
		Timeout     string            `json:"timeout"`
		Priority    string            `json:"priority"`
		Tags        []string          `json:"tags"`
	}
	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid JSON: " + err.Error()})
		return
	}
	if input.Name == "" {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "name is required"})
		return
	}

	now := time.Now().UTC()
	tmpl := &storage.Template{
		ID:          uuid.New().String(),
		Name:        input.Name,
		Description: input.Description,
		Claude:      input.Claude,
		Timeout:     input.Timeout,
		Priority:    input.Priority,
		Tags:        input.Tags,
		CreatedAt:   now,
		UpdatedAt:   now,
	}
	if tmpl.Priority == "" {
		tmpl.Priority = "normal"
	}
	if tmpl.Tags == nil {
		tmpl.Tags = []string{}
	}

	if err := s.store.CreateTemplate(tmpl); err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusCreated, tmpl)
}

func (s *Server) handleGetTemplate(w http.ResponseWriter, r *http.Request) {
	id := r.PathValue("id")
	tmpl, err := s.store.GetTemplate(id)
	if err != nil {
		if errors.Is(err, storage.ErrTemplateNotFound) {
			writeJSON(w, http.StatusNotFound, map[string]string{"error": "template not found"})
			return
		}
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, tmpl)
}

// handleUpdateTemplate fully replaces all fields of the template identified by {id}.
// All fields from the request body overwrite existing values; name is required.
func (s *Server) handleUpdateTemplate(w http.ResponseWriter, r *http.Request) {
	id := r.PathValue("id")
	existing, err := s.store.GetTemplate(id)
	if err != nil {
		if errors.Is(err, storage.ErrTemplateNotFound) {
			writeJSON(w, http.StatusNotFound, map[string]string{"error": "template not found"})
			return
		}
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}

	var input struct {
		Name        string            `json:"name"`
		Description string            `json:"description"`
		Claude      task.ClaudeConfig `json:"claude"`
		Timeout     string            `json:"timeout"`
		Priority    string            `json:"priority"`
		Tags        []string          `json:"tags"`
	}
	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid JSON: " + err.Error()})
		return
	}
	if input.Name == "" {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "name is required"})
		return
	}

	existing.Name = input.Name
	existing.Description = input.Description
	existing.Claude = input.Claude
	existing.Timeout = input.Timeout
	existing.Priority = input.Priority
	if input.Tags != nil {
		existing.Tags = input.Tags
	}
	existing.UpdatedAt = time.Now().UTC()

	if err := s.store.UpdateTemplate(existing); err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, existing)
}

func (s *Server) handleDeleteTemplate(w http.ResponseWriter, r *http.Request) {
	id := r.PathValue("id")
	err := s.store.DeleteTemplate(id)
	if err != nil {
		if errors.Is(err, storage.ErrTemplateNotFound) {
			writeJSON(w, http.StatusNotFound, map[string]string{"error": "template not found"})
			return
		}
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}
	w.WriteHeader(http.StatusNoContent)
}