package main

import (
	"context"
	"encoding/json"
	"io"
	"os"
	"time"
)

// runCombatMergeCLI folds a JSON array of cumulative session snapshots (stdin)
// through combatSessionDelta + combatMergeIntoLifetime and prints the resulting
// lifetime, mirroring exactly what the combat_stats handler accumulates. Used to
// diff the Go accumulator against the Python functions on identical input.
func runCombatMergeCLI() {
	raw, _ := io.ReadAll(os.Stdin)
	var snapshots []map[string]any
	if err := json.Unmarshal(raw, &snapshots); err != nil {
		os.Stderr.WriteString("combat-merge: invalid JSON: " + err.Error() + "\n")
		os.Exit(1)
	}
	lifetime := map[string]any{}
	var last map[string]any
	for _, s := range snapshots {
		var delta map[string]any
		if last != nil {
			delta = combatSessionDelta(s, last)
		} else {
			delta = s
		}
		lifetime = combatMergeIntoLifetime(lifetime, delta)
		last = s
	}
	out, _ := json.Marshal(lifetime)
	os.Stdout.Write(out)
}

// Combat stats accumulation — a faithful port of main.py's
// _combat_session_delta / _combat_merge_into_lifetime (incl. the documented
// quirk that offense/defense use the latest snapshot rather than a true delta).
// JSON numbers decode to float64; Go marshals whole floats without a decimal,
// so the stored JSONB matches Python's integer output.

func num(v any) float64 {
	switch x := v.(type) {
	case float64:
		return x
	case int:
		return float64(x)
	case int64:
		return float64(x)
	}
	return 0
}

func asMap(v any) map[string]any {
	if m, ok := v.(map[string]any); ok {
		return m
	}
	return map[string]any{}
}

func combatSessionDelta(newS, oldS map[string]any) map[string]any {
	delta := map[string]any{
		"total_damage_given":    num(newS["total_damage_given"]) - num(oldS["total_damage_given"]),
		"total_damage_received": num(newS["total_damage_received"]) - num(oldS["total_damage_received"]),
		"total_kills":           num(newS["total_kills"]) - num(oldS["total_kills"]),
		"total_aetheria_surges": num(newS["total_aetheria_surges"]) - num(oldS["total_aetheria_surges"]),
		"total_cloak_surges":    num(newS["total_cloak_surges"]) - num(oldS["total_cloak_surges"]),
		"monsters":              map[string]any{},
	}
	newMonsters := asMap(newS["monsters"])
	oldMonsters := asMap(oldS["monsters"])
	dMonsters := delta["monsters"].(map[string]any)
	for name, nmv := range newMonsters {
		nm := asMap(nmv)
		om := asMap(oldMonsters[name])
		dm := map[string]any{
			"name":            name,
			"kill_count":      num(nm["kill_count"]) - num(om["kill_count"]),
			"damage_given":    num(nm["damage_given"]) - num(om["damage_given"]),
			"damage_received": num(nm["damage_received"]) - num(om["damage_received"]),
			"aetheria_surges": num(nm["aetheria_surges"]) - num(om["aetheria_surges"]),
			"cloak_surges":    num(nm["cloak_surges"]) - num(om["cloak_surges"]),
			"offense":         asMap(nm["offense"]), // latest snapshot, per main.py
			"defense":         asMap(nm["defense"]),
		}
		if num(dm["kill_count"]) > 0 || num(dm["damage_given"]) > 0 || num(dm["damage_received"]) > 0 {
			dMonsters[name] = dm
		}
	}
	return delta
}

func combatMergeIntoLifetime(lifetime, delta map[string]any) map[string]any {
	if len(lifetime) == 0 {
		lifetime = map[string]any{
			"total_damage_given": float64(0), "total_damage_received": float64(0),
			"total_kills": float64(0), "total_aetheria_surges": float64(0),
			"total_cloak_surges": float64(0), "monsters": map[string]any{},
		}
	}
	lifetime["total_damage_given"] = num(lifetime["total_damage_given"]) + num(delta["total_damage_given"])
	lifetime["total_damage_received"] = num(lifetime["total_damage_received"]) + num(delta["total_damage_received"])
	lifetime["total_kills"] = num(lifetime["total_kills"]) + num(delta["total_kills"])
	lifetime["total_aetheria_surges"] = num(lifetime["total_aetheria_surges"]) + num(delta["total_aetheria_surges"])
	lifetime["total_cloak_surges"] = num(lifetime["total_cloak_surges"]) + num(delta["total_cloak_surges"])

	ltMonsters := asMap(lifetime["monsters"])
	lifetime["monsters"] = ltMonsters
	for name, dmv := range asMap(delta["monsters"]) {
		dm := asMap(dmv)
		lmv, ok := ltMonsters[name]
		if !ok {
			lmv = map[string]any{
				"name": name, "kill_count": float64(0), "damage_given": float64(0),
				"damage_received": float64(0), "aetheria_surges": float64(0),
				"cloak_surges": float64(0), "offense": map[string]any{}, "defense": map[string]any{},
			}
			ltMonsters[name] = lmv
		}
		lm := asMap(lmv)
		lm["kill_count"] = num(lm["kill_count"]) + num(dm["kill_count"])
		lm["damage_given"] = num(lm["damage_given"]) + num(dm["damage_given"])
		lm["damage_received"] = num(lm["damage_received"]) + num(dm["damage_received"])
		lm["aetheria_surges"] = num(lm["aetheria_surges"]) + num(dm["aetheria_surges"])
		lm["cloak_surges"] = num(lm["cloak_surges"]) + num(dm["cloak_surges"])
		for _, side := range []string{"offense", "defense"} {
			deltaSide := asMap(dm[side])
			if len(deltaSide) == 0 {
				continue
			}
			ltSide := asMap(lm[side])
			lm[side] = ltSide
			for atkType, byElV := range deltaSide {
				ltByEl := asMap(ltSide[atkType])
				ltSide[atkType] = ltByEl
				for el, statsV := range asMap(byElV) {
					stats := asMap(statsV)
					ltS := asMap(ltByEl[el])
					if len(ltS) == 0 {
						ltS = map[string]any{
							"total_attacks": float64(0), "failed_attacks": float64(0), "crits": float64(0),
							"total_normal_damage": float64(0), "max_normal_damage": float64(0),
							"total_crit_damage": float64(0), "max_crit_damage": float64(0),
						}
					}
					ltByEl[el] = ltS
					ltS["total_attacks"] = num(ltS["total_attacks"]) + num(stats["total_attacks"])
					ltS["failed_attacks"] = num(ltS["failed_attacks"]) + num(stats["failed_attacks"])
					ltS["crits"] = num(ltS["crits"]) + num(stats["crits"])
					ltS["total_normal_damage"] = num(ltS["total_normal_damage"]) + num(stats["total_normal_damage"])
					ltS["max_normal_damage"] = maxF(num(ltS["max_normal_damage"]), num(stats["max_normal_damage"]))
					ltS["total_crit_damage"] = num(ltS["total_crit_damage"]) + num(stats["total_crit_damage"])
					ltS["max_crit_damage"] = maxF(num(ltS["max_crit_damage"]), num(stats["max_crit_damage"]))
				}
			}
		}
	}
	return lifetime
}

func maxF(a, b float64) float64 {
	if a > b {
		return a
	}
	return b
}

// handleCombatStats mirrors main.py:3305: compute the session delta vs the last
// snapshot, merge into the (DB-backed) lifetime, persist lifetime + the session
// snapshot (delete-then-insert), and update the live overlay.
func (i *Ingestor) handleCombatStats(ctx context.Context, data map[string]any) {
	char := toStr(data["character_name"])
	if char == "" {
		return
	}
	sessionV, hasSession := data["session"]
	sessionID := toStr(data["session_id"])

	if hasSession && sessionV != nil {
		sessionData := asMap(sessionV)
		prevKey := char + ":" + sessionID

		i.mu.Lock()
		prev, hadPrev := i.combatLastSession[prevKey]
		i.combatLastSession[prevKey] = sessionData
		i.mu.Unlock()

		var delta map[string]any
		if hadPrev {
			delta = combatSessionDelta(sessionData, prev)
		} else {
			delta = sessionData
		}

		// Load lifetime from cache, else DB (else empty).
		i.mu.Lock()
		lifetime, cached := i.combatLifetimeCache[char]
		i.mu.Unlock()
		if !cached {
			lifetime = map[string]any{}
			if row, err := queryRowAsMap(ctx, i.pool,
				`SELECT stats_data FROM combat_stats WHERE character_name=$1`, char); err == nil && row != nil {
				if m := asJSONMap(row["stats_data"]); m != nil {
					lifetime = m
				}
			}
		}
		lifetime = combatMergeIntoLifetime(lifetime, delta)
		i.mu.Lock()
		i.combatLifetimeCache[char] = lifetime
		i.mu.Unlock()

		now := time.Now().UTC()
		ltJSON, _ := json.Marshal(lifetime)
		// delete-then-insert lifetime (no ON CONFLICT, matching Python)
		if _, err := i.pool.Exec(ctx, `DELETE FROM combat_stats WHERE character_name=$1`, char); err == nil {
			if _, err := i.pool.Exec(ctx,
				`INSERT INTO combat_stats (character_name,timestamp,stats_data) VALUES ($1,$2,$3)`,
				char, now, ltJSON); err != nil {
				i.log.Error("combat_stats insert failed", "err", err, "char", char)
			}
		}
		if sessionID != "" {
			sdJSON, _ := json.Marshal(sessionData)
			if _, err := i.pool.Exec(ctx,
				`DELETE FROM combat_stats_sessions WHERE character_name=$1 AND session_id=$2`, char, sessionID); err == nil {
				if _, err := i.pool.Exec(ctx,
					`INSERT INTO combat_stats_sessions (character_name,session_id,timestamp,stats_data) VALUES ($1,$2,$3,$4)`,
					char, sessionID, now, sdJSON); err != nil {
					i.log.Error("combat_stats_sessions insert failed", "err", err, "char", char)
				}
			}
		}
		data["lifetime"] = lifetime
	}

	i.mu.Lock()
	i.liveCombatStats[char] = data
	i.mu.Unlock()
}