package api

import (
	"context"
	"database/sql"
	"errors"
	"net/http"
	"strconv"
	"strings"
	"time"
)

// Summary queries never load log bodies; history cannot inflate a page response.
const buildSummaryColumns = "id,version,status,error,image_id,created_at,requested_by,COALESCE(recipe_rev,''),COALESCE(platform,''),COALESCE(finished_at,''),experimental"

func scanBuildSummary(row interface{ Scan(...any) error }, b *buildRecord) error {
	return row.Scan(&b.ID, &b.Version, &b.Status, &b.Error, &b.ImageID, &b.Created, &b.RequestedBy, &b.RecipeRev, &b.Platform, &b.Finished, &b.Experimental)
}

func (a *API) listBuilds(w http.ResponseWriter, r *http.Request) {
	limit, offset := 20, 0
	for key, dest := range map[string]*int{"limit": &limit, "offset": &offset} {
		if values, ok := r.URL.Query()[key]; ok {
			if len(values) != 1 {
				fail(w, 400, "invalid pagination")
				return
			}
			value, err := strconv.Atoi(values[0])
			if err != nil || value < 0 || (key == "limit" && (value < 1 || value > 100)) {
				fail(w, 400, "invalid pagination")
				return
			}
			*dest = value
		}
	}
	ctx, cancel := context.WithTimeout(r.Context(), 15*time.Second)
	defer cancel()
	buildQueue.Lock()
	err := a.ensureBuilds()
	buildQueue.Unlock()
	if err != nil {
		fail(w, 500, "database error")
		return
	}
	rows, err := a.s.DB.QueryContext(ctx, "SELECT "+buildSummaryColumns+" FROM image_builds ORDER BY created_at DESC,id DESC LIMIT ? OFFSET ?", limit+1, offset)
	if err != nil {
		fail(w, 500, "database error")
		return
	}
	result := []buildRecord{}
	for rows.Next() {
		var b buildRecord
		if err = scanBuildSummary(rows, &b); err != nil {
			break
		}
		result = append(result, b)
	}
	if err == nil {
		err = rows.Err()
	}
	rows.Close()
	if err != nil {
		fail(w, 500, "database error")
		return
	}
	hasMore := len(result) > limit
	if hasMore {
		result = result[:limit]
	}
	if err := a.reconcileBuilds(ctx, result); err != nil {
		fail(w, 502, "docker image reconciliation failed")
		return
	}
	a.startBuildWorker()
	w.Header().Set("X-Has-More", strconv.FormatBool(hasMore))
	writeJSON(w, result)
}

func (a *API) buildDetail(w http.ResponseWriter, r *http.Request) {
	if _, _, err := a.user(r); err != nil {
		fail(w, 401, "authentication required")
		return
	}
	if r.Method != http.MethodGet {
		fail(w, 405, "method not allowed")
		return
	}
	id := strings.TrimPrefix(r.URL.Path, "/api/builds/")
	if id == "" || len(id) > 128 || strings.Contains(id, "/") {
		fail(w, 404, "build not found")
		return
	}
	ctx, cancel := context.WithTimeout(r.Context(), 15*time.Second)
	defer cancel()
	buildQueue.Lock()
	err := a.ensureBuilds()
	buildQueue.Unlock()
	var b buildRecord
	if err == nil {
		err = a.s.DB.QueryRowContext(ctx, "SELECT "+buildSummaryColumns+",logs FROM image_builds WHERE id=?", id).Scan(&b.ID, &b.Version, &b.Status, &b.Error, &b.ImageID, &b.Created, &b.RequestedBy, &b.RecipeRev, &b.Platform, &b.Finished, &b.Experimental, &b.Logs)
	}
	if errors.Is(err, sql.ErrNoRows) {
		fail(w, 404, "build not found")
		return
	}
	if err != nil {
		fail(w, 500, "database error")
		return
	}
	b.Logs = sanitizeBuildLog(b.Logs)
	writeJSON(w, b)
}