package api

import (
	"database/sql"
	"net/http"

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

	"work-queue-api/internal/model"
)

type createProjectRequest struct {
	Name        string  `json:"name"`
	ExternalRef *string `json:"external_ref"`
}

type patchProjectRequest struct {
	Name        *string `json:"name"`
	ExternalRef *string `json:"external_ref"`
}

func (s *Server) handleCreateProject(w http.ResponseWriter, r *http.Request) {
	var req createProjectRequest
	if err := decodeJSON(r, &req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid json body")
		return
	}
	if req.Name == "" {
		writeError(w, http.StatusBadRequest, "name is required")
		return
	}

	now := nowUTC()
	project := model.Project{
		ID:          uuid.NewString(),
		Name:        req.Name,
		ExternalRef: req.ExternalRef,
		CreatedAt:   now,
		UpdatedAt:   now,
	}

	_, err := s.db.Exec(`INSERT INTO projects (id, name, external_ref, created_at, updated_at) VALUES (?, ?, ?, ?, ?)`,
		project.ID, project.Name, project.ExternalRef, project.CreatedAt.Format(timeLayout), project.UpdatedAt.Format(timeLayout),
	)
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}

	writeJSON(w, http.StatusCreated, project)
}

func (s *Server) handleListProjects(w http.ResponseWriter, r *http.Request) {
	rows, err := s.db.Query(`SELECT id, name, external_ref, created_at, updated_at FROM projects ORDER BY created_at ASC`)
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	defer rows.Close()

	var projects []model.Project
	for rows.Next() {
		project, err := scanProject(rows)
		if err != nil {
			writeError(w, http.StatusInternalServerError, err.Error())
			return
		}
		projects = append(projects, project)
	}

	writeJSON(w, http.StatusOK, projects)
}

func (s *Server) handleGetProject(w http.ResponseWriter, r *http.Request) {
	project, err := s.fetchProject(chi.URLParam(r, "id"))
	if err == sql.ErrNoRows {
		writeError(w, http.StatusNotFound, "project not found")
		return
	}
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, project)
}

func (s *Server) handlePatchProject(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")
	project, err := s.fetchProject(id)
	if err == sql.ErrNoRows {
		writeError(w, http.StatusNotFound, "project not found")
		return
	}
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}

	var req patchProjectRequest
	if err := decodeJSON(r, &req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid json body")
		return
	}

	if req.Name != nil {
		if *req.Name == "" {
			writeError(w, http.StatusBadRequest, "name cannot be empty")
			return
		}
		project.Name = *req.Name
	}
	if req.ExternalRef != nil {
		project.ExternalRef = req.ExternalRef
	}
	project.UpdatedAt = nowUTC()

	_, err = s.db.Exec(`UPDATE projects SET name = ?, external_ref = ?, updated_at = ? WHERE id = ?`,
		project.Name, project.ExternalRef, project.UpdatedAt.Format(timeLayout), project.ID,
	)
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}

	writeJSON(w, http.StatusOK, project)
}

func (s *Server) fetchProject(id string) (model.Project, error) {
	row := s.db.QueryRow(`SELECT id, name, external_ref, created_at, updated_at FROM projects WHERE id = ?`, id)
	return scanProject(row)
}