package fetch

import (
	"encoding/json"
	"fmt"
	"log/slog"
	"slices"
	"time"

	"github.com/spf13/cobra"

	"git.avsdev.uk/Go/job-search/internal/cli"
	"git.avsdev.uk/Go/job-search/internal/findatender"
	"git.avsdev.uk/Go/job-search/internal/types"
)

// Release tags for each stage of a procedure, from the OCDS releaseTag
// codelist. Cancellations are left out, as a cancelled procedure is no longer
// at any stage.
var stageTags = map[string][]string{
	"planning":    {"planning", "planningUpdate"},
	"opportunity": {"tender", "tenderAmendment", "tenderUpdate"},
	"award": {
		"award", "awardUpdate",
		"contract", "contractUpdate", "contractAmendment",
		"implementation", "implementationUpdate", "contractTermination",
	},
}

// filter keeps the opportunities whose latest release is at stage. Releases
// are oldest first, so the last one is the procedure's current stage.
func filter(
	opportunities []*types.Opportunity, stage string,
) []*types.Opportunity {
	var matching []*types.Opportunity

	for _, opportunity := range opportunities {
		if len(opportunity.Releases) == 0 {
			continue
		}
		latest := opportunity.Releases[len(opportunity.Releases)-1]
		for _, tag := range latest.Tags {
			if slices.Contains(stageTags[stage], tag.Tag) {
				matching = append(matching, opportunity)
				break
			}
		}
	}

	return matching
}

func commandOnce(opts *cli.Options) *cobra.Command {
	cmd := &cobra.Command{
		Use:   "once",
		Short: "Fetch current opportunities - single shot",
		PersistentPreRun: func(cmd *cobra.Command, args []string) {
			slog.Debug("command persistent pre-run", "command", "fetch.once")
		},
		PersistentPostRun: func(cmd *cobra.Command, args []string) {
			slog.Debug("command persistent post-run", "command", "fetch.once")
		},
		RunE: func(cmd *cobra.Command, args []string) error {
			slog.Debug("command run", "command", "fetch.once")

			conf, err := opts.RunSetup(cmd, true, true)
			if err != nil {
				return fmt.Errorf("load configuration: %w", err)
			}

			since, sinceErr := cmd.Flags().GetTime("since")
			if sinceErr != nil {
				return sinceErr
			}

			findATender := findatender.New(conf, conf.Sources.FindATender.APIRoot)
			defer findATender.Shutdown()

			ignoreRateLimit, _ := cmd.Flags().GetBool("ignore-rate-limit")

			results, err := findATender.FetchAll(since, !ignoreRateLimit)
			if err != nil {
				return err
			}

			planning, _ := cmd.Flags().GetBool("planning")
			opportunities, _ := cmd.Flags().GetBool("opportunities")
			awards, _ := cmd.Flags().GetBool("awards")

			filterTag := ""
			if planning {
				filterTag = "planning"
			}
			if opportunities {
				filterTag = "opportunity"
			}
			if awards {
				filterTag = "award"
			}

			if filterTag != "" {
				results = filter(results, filterTag)
			}

			encoded, err := json.MarshalIndent(results, "", "  ")
			if err != nil {
				return err
			}
			fmt.Println(string(encoded))

			return nil
		},
	}
	cmd.Flags().Time(
		"since",
		time.Time{},
		[]string{
			time.DateOnly, time.DateTime,
		},
		"contract updates published since YYYY-MM-DD[ hh:mm:ss]",
	)
	cmd.Flags().Bool(
		"planning",
		false,
		"only return planning (i.e. exclude opportunities and awards)",
	)
	cmd.Flags().Bool(
		"opportunities",
		false,
		"only return opportunities (i.e. exclude awards and planning)",
	)
	cmd.Flags().Bool(
		"awards",
		false,
		"only return awards (i.e. exclude planning and opportunities)",
	)
	cmd.Flags().Bool(
		"ignore-rate-limit", false, "ignore the rate limit and fail if exceeded",
	)
	cmd.MarkFlagsMutuallyExclusive("planning", "opportunities", "awards")

	return cmd
}