package handlers

import (
	"encoding/json"
	"log/slog"
	"net/http"
	"strings"

	"github.com/go-chi/chi/v5"

	"git.unkin.net/unkin/forgebot/internal/database"
	"git.unkin.net/unkin/forgebot/internal/provider/gitea"
	"git.unkin.net/unkin/forgebot/pkg/models"
)

type TasksHandler struct {
	db       *database.DB
	provider *gitea.Client
}

func NewTasksHandler(db *database.DB, provider *gitea.Client) *TasksHandler {
	return &TasksHandler{db: db, provider: provider}
}

func (h *TasksHandler) List(w http.ResponseWriter, r *http.Request) {
	status := r.URL.Query().Get("status")
	repository := r.URL.Query().Get("repository")

	tasks, err := h.db.ListTasks(r.Context(), status, repository)
	if err != nil {
		slog.Error("failed to list tasks", "error", err)
		http.Error(w, "internal error", http.StatusInternalServerError)
		return
	}
	if tasks == nil {
		tasks = []models.Task{}
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(tasks)
}

func (h *TasksHandler) Create(w http.ResponseWriter, r *http.Request) {
	var req models.CreateTaskRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "invalid request body", http.StatusBadRequest)
		return
	}

	if req.Command == "" || req.Repository == "" {
		http.Error(w, "command and repository are required", http.StatusBadRequest)
		return
	}

	if !models.ValidCommands[req.Command] {
		http.Error(w, "invalid command", http.StatusBadRequest)
		return
	}

	task, err := h.db.CreateTask(r.Context(), req)
	if err != nil {
		slog.Error("failed to create task", "error", err)
		http.Error(w, "internal error", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusCreated)
	json.NewEncoder(w).Encode(task)
}

func (h *TasksHandler) Get(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")

	task, err := h.db.GetTask(r.Context(), id)
	if err != nil {
		http.Error(w, "task not found", http.StatusNotFound)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(task)
}

func (h *TasksHandler) UpdateStatus(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")

	var req models.UpdateTaskRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "invalid request body", http.StatusBadRequest)
		return
	}

	if err := h.db.UpdateTaskStatus(r.Context(), id, req); err != nil {
		slog.Error("failed to update task", "error", err, "id", id)
		http.Error(w, "internal error", http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusNoContent)
}

func (h *TasksHandler) PostComment(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")

	var req models.CommentRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "invalid request body", http.StatusBadRequest)
		return
	}

	task, err := h.db.GetTask(r.Context(), id)
	if err != nil {
		http.Error(w, "task not found", http.StatusNotFound)
		return
	}

	parts := strings.SplitN(task.Repository, "/", 2)
	if len(parts) != 2 {
		http.Error(w, "invalid repository format", http.StatusInternalServerError)
		return
	}

	issueNum := task.IssueNumber
	if task.PRNumber > 0 {
		issueNum = task.PRNumber
	}

	if err := h.provider.PostComment(parts[0], parts[1], issueNum, req.Body); err != nil {
		slog.Error("failed to post comment", "error", err, "task", id)
		http.Error(w, "failed to post comment", http.StatusBadGateway)
		return
	}

	w.WriteHeader(http.StatusNoContent)
}